diff --git a/quasar.config.ts b/quasar.config.ts
index 4d94787..3821349 100644
--- a/quasar.config.ts
+++ b/quasar.config.ts
@@ -106,7 +106,7 @@ export default defineConfig((ctx) => {
           color: 'primary',
           avatar: 'https://cdn.quasar.dev/img/boy-avatar.png',
         },
-        dark: false,
+        dark: "auto",
       },
 
       // iconSet: 'material-icons', // Quasar icon set
diff --git a/src/i18n/en-ca/index.ts b/src/i18n/en-ca/index.ts
index 2697fe5..15683c6 100644
--- a/src/i18n/en-ca/index.ts
+++ b/src/i18n/en-ca/index.ts
@@ -179,6 +179,7 @@ export default {
       hints: {
         amount_or_mileage:"Either amount or mileage, not both",
         comment_required:"A comment required",
+        attach_file:"Attach File"
       },
       mileage:"mileage",
       open_btn:"list of expenses",
diff --git a/src/i18n/fr-ca/index.ts b/src/i18n/fr-ca/index.ts
index 4a5a9ba..0471595 100644
--- a/src/i18n/fr-ca/index.ts
+++ b/src/i18n/fr-ca/index.ts
@@ -179,6 +179,7 @@ export default {
       hints: {
         amount_or_mileage:"Soit dépense ou kilométrage, pas les deux",
         comment_required:"un commentaire est requis",
+        attach_file:"Pièce jointe"
       },
       mileage:"Kilométrage",
       open_btn:"Liste des Dépenses",
diff --git a/src/modules/shared/composables/use-toggle.ts b/src/modules/shared/composables/use-toggle.ts
new file mode 100644
index 0000000..64a026c
--- /dev/null
+++ b/src/modules/shared/composables/use-toggle.ts
@@ -0,0 +1,17 @@
+import { ref } from "vue";
+
+//date picker state
+export const useToggle = (initial = false) => {
+  const state = ref<boolean>(initial);
+
+  const setTrue  = () => { state.value = true;         };
+  const setFalse = () => { state.value = false;        };
+  const toggle   = () => { state.value = !state.value; };
+
+  return { 
+    state,
+    setTrue,
+    setFalse,
+    toggle
+ };
+};
\ No newline at end of file
diff --git a/src/modules/timesheet-approval/components/graphs/timesheet-approval-employee-expenses-chart.vue b/src/modules/timesheet-approval/components/graphs/timesheet-approval-employee-expenses-chart.vue
index 4090ea9..db49823 100644
--- a/src/modules/timesheet-approval/components/graphs/timesheet-approval-employee-expenses-chart.vue
+++ b/src/modules/timesheet-approval/components/graphs/timesheet-approval-employee-expenses-chart.vue
@@ -5,7 +5,7 @@
     import { useQuasar } from 'quasar';
     import { Chart as ChartJS, Title, Tooltip, Legend, BarElement, CategoryScale, LinearScale, TimeScale, type ChartData, type ChartDataset } from 'chart.js';
     import type { PayPeriodEmployeeDetails } from 'src/modules/timesheet-approval/types/timesheet-approval-pay-period-employee-details-interface';
-    import type { Expense } from 'src/modules/timesheets/types/timesheet-details-interface';
+    import type { Expense } from 'src/modules/timesheets/types/expense.interfaces';
 
     const { t } = useI18n();
     const $q = useQuasar();
diff --git a/src/modules/timesheet-approval/components/timesheet-approval-employee-details-shifts-row.vue b/src/modules/timesheet-approval/components/timesheet-approval-employee-details-shifts-row.vue
index 2eca764..1372023 100644
--- a/src/modules/timesheet-approval/components/timesheet-approval-employee-details-shifts-row.vue
+++ b/src/modules/timesheet-approval/components/timesheet-approval-employee-details-shifts-row.vue
@@ -1,6 +1,7 @@
 <script setup lang="ts">
-    import type { Shift } from 'src/modules/timesheets/types/timesheet-shift-interface';
 import { ref } from 'vue';
+import type { Shift } from 'src/modules/timesheets/types/shift.interfaces';
+
 
     const props = defineProps<{
         shift: Shift;
@@ -52,7 +53,7 @@ import { ref } from 'vue';
                 :key="index"
             > 
                 <q-icon
-                    v-if="props.shift.type !== ''"
+                    v-if="props.shift.type"
                     name="double_arrow"
                     :color="icon_data.color"
                     size="24px"
@@ -78,7 +79,7 @@ import { ref } from 'vue';
         >
             <!-- chat_bubble_outline or announcement -->
             <q-btn
-                v-if="props.shift.type !== ''"
+                v-if="props.shift.type"
                 flat 
                 dense
                 icon="chat_bubble_outline"
@@ -87,7 +88,7 @@ import { ref } from 'vue';
 
             <!-- insert_drive_file or request_quote -->
             <q-btn
-                v-if="props.shift.type !== ''"
+                v-if="props.shift.type"
                 flat 
                 dense
                 icon="attach_money"        
diff --git a/src/modules/timesheet-approval/components/timesheet-approval-employee-details-shifts.vue b/src/modules/timesheet-approval/components/timesheet-approval-employee-details-shifts.vue
index 14c2d6c..bce3ecf 100644
--- a/src/modules/timesheet-approval/components/timesheet-approval-employee-details-shifts.vue
+++ b/src/modules/timesheet-approval/components/timesheet-approval-employee-details-shifts.vue
@@ -2,8 +2,9 @@
     import TimesheetApprovalEmployeeDetailsShiftsRow from 'src/modules/timesheet-approval/components/timesheet-approval-employee-details-shifts-row.vue';
     import TimesheetApprovalEmployeeDetailsShiftsRowHeader from 'src/modules/timesheet-approval/components/timesheet-approval-employee-details-shifts-row-header.vue';
     import type { PayPeriod } from 'src/modules/shared/types/pay-period-interface';
-    import { default_shift, type Shift } from 'src/modules/timesheets/types/timesheet-shift-interface';
     import type { PayPeriodEmployeeDetails } from 'src/modules/timesheet-approval/types/timesheet-approval-pay-period-employee-details-interface';
+    import type { Shift } from 'src/modules/timesheets/types/shift.interfaces';
+    import { default_shift } from 'src/modules/timesheets/types/shift.defaults';
 
     const props = defineProps<{
         rawData: PayPeriodEmployeeDetails;
diff --git a/src/modules/timesheet-approval/types/timesheet-approval-pay-period-employee-details-interface.ts b/src/modules/timesheet-approval/types/timesheet-approval-pay-period-employee-details-interface.ts
index 01ce1b9..21dbd0b 100644
--- a/src/modules/timesheet-approval/types/timesheet-approval-pay-period-employee-details-interface.ts
+++ b/src/modules/timesheet-approval/types/timesheet-approval-pay-period-employee-details-interface.ts
@@ -1,4 +1,6 @@
-import { default_timesheet_details_week, type TimesheetDetailsWeek } from "src/modules/timesheets/types/timesheet-details-interface";
+import { defaultTimesheetDetailsWeek } from "src/modules/timesheets/types/timesheet.defaults";
+import type { TimesheetDetailsWeek } from "src/modules/timesheets/types/timesheet.interfaces";
+
 
 export interface PayPeriodEmployeeDetails {
     week1: TimesheetDetailsWeek;
@@ -6,6 +8,6 @@ export interface PayPeriodEmployeeDetails {
 };
 
 export const default_pay_period_employee_details = {
-    week1: default_timesheet_details_week(),
-    week2: default_timesheet_details_week(),
+    week1: defaultTimesheetDetailsWeek(),
+    week2: defaultTimesheetDetailsWeek(),
 }
\ No newline at end of file
diff --git a/src/modules/timesheets/components/expenses/expense-form.vue b/src/modules/timesheets/components/expenses/expense-form.vue
new file mode 100644
index 0000000..7522815
--- /dev/null
+++ b/src/modules/timesheets/components/expenses/expense-form.vue
@@ -0,0 +1,185 @@
+<script setup lang="ts">
+import type { TimesheetExpense } from '../../types/expense.interfaces';
+import type { ExpenseType }      from '../../types/expense.types';
+/* eslint-disable */
+
+//---------------- v-models ------------------
+const draft = defineModel<Partial<TimesheetExpense>>('draft');
+const files = defineModel<File[] | null>('files'); 
+const datePickerOpen = defineModel<boolean | null>('datePickerOpen', {default: false });
+
+//------------------ props ------------------
+const props = defineProps<{
+    type_options: { label: string; value: ExpenseType }[];
+    show_amount: boolean;
+    is_readonly: boolean;
+    rules: {
+        typeRequired:    (val: unknown) => true | string;
+        amountRequired:  (val: unknown) => true | string;
+        mileageRequired: (val: unknown) => true | string;
+        commentRequired: (val: unknown) => true | string;
+        commentTooLong:  (val: unknown) => true | string;
+    };
+    comment_max_length: number;
+    setType: (val: ExpenseType) => void;
+}>();
+
+//------------------ emits ------------------
+const emit = defineEmits<{
+    (e: 'submit'): void;
+}>();
+
+</script>
+
+<template>
+    <q-form 
+        flat 
+        v-if="!is_readonly"
+        @submit.prevent="emit('submit')"
+    >
+        <div class="text-subtitle2 q-py-sm">
+            {{ $t('timesheet.expense.add_expense')}}
+        </div>
+        <div class="row justify-between">
+
+            <!-- date selection input -->
+            <q-input
+                v-model.date="draft!.date"
+                dense
+                filled
+                readonly
+                stack-label
+                class="col q-px-xs"
+                color="primary"
+                :label="$t('timesheet.expense.date')"
+            >
+            <template #before>
+                <q-btn
+                    push
+                    dense
+                    icon="event"
+                    color="primary"
+                    @click="datePickerOpen = true"
+                />
+                <q-dialog v-model="datePickerOpen">
+                    <q-date 
+                        v-model="draft!.date"
+                        @update:model-value="datePickerOpen = false"
+                        mask="YYYY-MM-DD"
+                    />    
+                </q-dialog>
+            </template>
+            </q-input>
+
+            <!-- expenses type selection -->
+            <q-select
+                v-model="draft!.type"
+                :options="type_options"
+                filled
+                dense
+                class="col q-px-xs"
+                color="primary"
+                emit-value
+                map-options
+                :label="$t('timesheet.expense.type')"
+                :rules="[ rules.typeRequired ]"
+                @update:model-value="val => setType(val as ExpenseType)"
+            />
+
+            <!-- amount input -->
+            <template v-if="show_amount">
+                <q-input
+                    key="amount"
+                    v-model.number="draft!.amount"
+                    filled
+                    input-class="text-right"
+                    dense
+                    stack-label
+                    clearable
+                    color="primary"
+                    class="col q-px-xs"
+                    :label="$t('timesheet.expense.amount')"
+                    suffix="$"
+                    lazy-rules="ondemand"
+                    :rules="[ rules.amountRequired ]"
+                />
+            </template>
+
+            <!-- mileage input -->
+            <template v-else>
+                <q-input
+                    key="mileage"
+                    v-model.number="draft!.mileage"
+                    filled
+                    input-class="text-right"
+                    dense
+                    stack-label
+                    clearable
+                    color="primary"
+                    class="col q-px-xs"
+                    :label="$t('timesheet.expense.mileage')"
+                    suffix="km"
+                    lazy-rules="ondemand"
+                    :rules="[ rules.mileageRequired ]"
+                />
+            </template>
+
+            <!-- employee comment input -->
+            <q-input
+                v-model="draft!.comment"
+                filled
+                color="primary"
+                type="text"
+                class="col q-px-sm"
+                dense
+                stack-label
+                clearable
+                :counter="true"
+                :maxlength="comment_max_length"
+                lazy-rules="ondemand"
+                :rules="[ rules.commentRequired, rules.commentTooLong ]"
+            >
+                <template #label>
+                    <span class="text-weight-bold ">
+                        {{ $t('timesheet.expense.employee_comment') }}
+                    </span>
+                </template>
+            </q-input>
+
+            <!-- import attach file section -->
+            <q-file
+                v-model="files"
+                :label="$t('timesheet.expense.hints.attach_file')"
+                filled
+                use-chips
+                multiple
+                stack-label
+                class="col"
+                style="max-width: 300px;"
+                dense
+            >
+                <template #prepend>
+                    <q-icon
+                        name="attach_file"
+                        size="sm"
+                        color="primary"
+                        
+                    />
+                </template>
+            </q-file>
+            
+            <!-- add btn section -->
+            <div>
+                <q-btn
+                    push
+                    dense
+                    color="primary"
+                    icon="add"
+                    size="sm"
+                    class="q-mt-sm q-ml-sm"
+                    type="submit"
+                />                
+            </div>
+        </div>
+    </q-form>
+</template>
\ No newline at end of file
diff --git a/src/modules/timesheets/components/expenses/expense-list.vue b/src/modules/timesheets/components/expenses/expense-list.vue
new file mode 100644
index 0000000..b16b310
--- /dev/null
+++ b/src/modules/timesheets/components/expenses/expense-list.vue
@@ -0,0 +1,98 @@
+<script setup lang="ts">
+import type { TimesheetExpense } from '../../types/expense.interfaces';
+import { expenseTypeIcon }  from '../../utils/expense.util';
+/* eslint-disable */
+const props = defineProps<{
+    items: TimesheetExpense[];
+    is_readonly: boolean;
+}>();
+
+const emit = defineEmits<{
+    (e: 'remove', index: number): void;
+}>();
+
+</script>
+
+<template>
+    <!-- liste des dépenses pré existantes -->
+    <q-list 
+        padding 
+        class="rounded-borders"
+
+    >
+        <q-item-label v-if="items.length === 0" class="text-italic q-px-sm">
+            {{ $t('timesheet.expense.empty_list') }}
+        </q-item-label>
+        <q-item
+            style="border: solid 1px lightgrey; border-radius: 7px;"
+            v-for="(expense, index) in items" :key="index"
+            class="q-my-xs shadow-1"
+        >
+            <!-- avatar type icon section -->
+            <q-item-section avatar>
+                <q-icon :name="expenseTypeIcon(expense.type)" color="primary"/>
+            </q-item-section>
+
+            <!-- amount or mileage section -->
+            <q-item-section top>
+                <q-item-label v-if="String(expense.type).trim().toUpperCase() === 'MILEAGE'">
+                    {{ expense.mileage?.toFixed(1) }} km
+                </q-item-label>
+                <q-item-label v-else>
+                    {{ expense.amount?.toFixed(2) }} $
+                </q-item-label>
+                
+                <!-- date label -->
+                <q-item-label caption lines="2">
+                        {{ $d(new Date(expense.date + 'T00:00:00'), { year:'numeric', month:'short', day: 'numeric', weekday: 'short'}) }}
+                </q-item-label>
+            </q-item-section>
+
+            <!-- attachment file icon -->
+            <q-item-section side>
+                <q-btn
+                    push   
+                    dense
+                    size="md"
+                    color="primary"
+                    class="q-mx-lg"
+                    icon="attach_file"
+                />
+            </q-item-section>
+
+            <!-- comment section -->
+            <q-item-section top>
+                <q-item-label lines="1">
+                    {{ $t('timesheet.expense.employee_comment') }}
+                </q-item-label>
+                <q-item-label caption lines="2">
+                    {{ expense.comment }}
+                </q-item-label>
+            </q-item-section>
+
+            <!-- supervisor comment section -->
+            <q-item-section top>
+                <q-item-label lines="1">
+                    {{ $t('timesheet.expense.supervisor_comment') }}
+                </q-item-label>
+                <q-item-label v-if="expense.supervisor_comment" caption lines="2">
+                    {{ expense.supervisor_comment }}    
+                </q-item-label>
+            </q-item-section>    
+
+            <!-- delete btn -->
+            <q-item-section side>
+                <q-btn
+                    v-if="!is_readonly"
+                    push
+                    dense
+                    size="xs"
+                    color="negative"
+                    icon="close"
+                    @click="emit('remove', index)"
+                />
+            </q-item-section>
+        </q-item>
+    </q-list>
+
+</template>
\ No newline at end of file
diff --git a/src/modules/timesheets/components/shift/shift-comment.vue b/src/modules/timesheets/components/expenses/expense-supervisor-comment.vue
similarity index 100%
rename from src/modules/timesheets/components/shift/shift-comment.vue
rename to src/modules/timesheets/components/expenses/expense-supervisor-comment.vue
diff --git a/src/modules/timesheets/components/expenses/timesheet-details-expenses.vue b/src/modules/timesheets/components/expenses/timesheet-details-expenses.vue
index f2c7690..f229af9 100644
--- a/src/modules/timesheets/components/expenses/timesheet-details-expenses.vue
+++ b/src/modules/timesheets/components/expenses/timesheet-details-expenses.vue
@@ -1,159 +1,115 @@
-
 <script setup lang="ts">
+import { useI18n } from 'vue-i18n';
 import { computed, ref } from 'vue';
-import { EXPENSE_TYPE, type ExpenseType, type TimesheetExpense } from '../../types/timesheet-expenses-interface';
-import { compute_expense_totals, ExpensesValidationError, normalize_expense, validate_expense_UI } from '../../utils/timesheet-expenses-validators';
-// import { date } from 'quasar';
-import { COMMENT_MAX_LENGTH } from '../../composables/use-shift-api';
+import { useExpenseForm }  from '../../composables/use-expense-form';
+import { useExpenseDraft } from '../../composables/use-expense-draft';
+import { useExpenseItems } from '../../composables/use-expense-items';
+import { COMMENT_MAX_LENGTH } from '../../constants/expense.constants';
+import { useToggle } from 'src/modules/shared/composables/use-toggle';
+import ExpenseList from './expense-list.vue';
+import ExpenseForm from './expense-form.vue';
+import { 
+    buildExpenseTypeOptions,
+    computeExpenseTotals,
+    makeExpenseRules,
+    buildExpenseSavePayload
+} from '../../utils/expense.util';
+import { EXPENSE_TYPE }     from '../../types/expense.types';
+import { ExpensesValidationError } from '../../types/expense-validation.interface';
+import type { TimesheetExpense } from '../../types/expense.interfaces';
 
 /* eslint-disable */
 
-//props
+const { t , locale } = useI18n();
+const rules = makeExpenseRules(t, COMMENT_MAX_LENGTH);
+
+//------------------ props ------------------
 const props = defineProps<{
     pay_period_no: number;
-    pay_year: number;
-    email: string;
-    is_approved?: boolean;
+    pay_year:      number;
+    email:         string;
+    is_approved?:  boolean;
     initial_expenses?: TimesheetExpense[];
 }>();
 
-//emits
+//------------------ emits ------------------
 const emit = defineEmits<{
     (e:'close'): void;
     (e: 'save', payload: {
         pay_period_no: number;
-        pay_year: number;
-        email: string;
+        pay_year:      number;
+        email:         string;
         expenses: TimesheetExpense[];
     }): void;
     (e: 'error', err: ExpensesValidationError): void;
 }>();
 
-//q-select mapper
-const type_options = computed(()=> EXPENSE_TYPE.map( val => ({ label: val, value: val })));
+//------------------ q-select mapper ------------------
+const type_options = computed(()=> {
+    void locale.value;
+    return buildExpenseTypeOptions(EXPENSE_TYPE, t);
+})
 
-//refs & states
-const items = ref<TimesheetExpense[]>(Array.isArray(props.initial_expenses) ? props.initial_expenses.map(normalize_expense): []);
-const formRef = ref<InstanceType<any> | null>(null);
-const triedSubmit = ref(false);
-
-const DEFAULT_TYPE: ExpenseType = 'EXPENSES'
-
-const draft = ref<Partial<TimesheetExpense>>({
-    date:'',
-    type: DEFAULT_TYPE,
-    comment:'',
-});
-
-// computeds
-const totals      = computed(()=> compute_expense_totals(items.value));
+//------------------ refs and computed ------------------
+const files               = ref<File[] | null>(null);
 const is_readonly = computed(()=> !!props.is_approved);
-const showMileage = computed(()=> (draft.value.type as string) === 'MILEAGE');
-const showAmount  = computed(()=> !showMileage.value);
 
-//helpers
-const reset_draft = () => {
-    draft.value.date = '';
-    draft.value.type = 'EXPENSES';
-    delete draft.value.amount;
-    delete draft.value.mileage;
-    draft.value.comment = '';
-};
-
-const set_draft_type   = (value: ExpenseType) => {
-    draft.value.type = value;
-    if (value === 'MILEAGE') {
-        delete draft.value.amount;
-    } else {
-        delete draft.value.mileage;
-    }
-};
-
-//actions
-const add_draft_as_item = () => {
-    const candidate: TimesheetExpense = normalize_expense({
-        date: draft.value.date,
-        type: normType(draft.value.type),
-        ...(typeof draft.value.amount  === 'number' ? { amount: draft.value.amount   }: {}),
-        ...(typeof draft.value.mileage === 'number' ? { mileage: draft.value.mileage }: {}),
-        comment: String(draft.value.comment ?? '').trim(),
-    } as TimesheetExpense);
+const { state: is_open_date_picker } = useToggle();
+const { draft, setType, reset, showAmount } = useExpenseDraft();
+const { validateAnd } = useExpenseForm();
+const { items, addFromDraft, removeAt, validateAll, payload } = useExpenseItems({
+    initial_expenses: props.initial_expenses,
+    draft,
+    is_approved: is_readonly,
+});
+const totals = computed(()=> computeExpenseTotals(items.value));
 
+//------------------ actions ------------------
+const onSave = () => {
     try {
-        validate_expense_UI(candidate, 'expense_draft');
-        items.value = [ ...items.value, candidate];
-        reset_draft();
-    } catch (err: any) {
-        const e = err instanceof ExpensesValidationError
-        ? err : new ExpensesValidationError({
-            status_code: 400,
-            message: String(err?.message || err)
-        });
-        emit('error', e);
-    }
-};
-
-const remove_item_at = (index: number) => {
-    if(props.is_approved) return;
-    if(index < 0 || index >= items.value.length) return;
-    items.value = items.value.filter((_,i) => i !== index);
-};
-
-const validate_all = () => {
-    for(const expense of items.value) {
-        validate_expense_UI(expense, 'expense_item');
-    }
-};
-
-const on_save = () => {
-    try {
-        validate_all();
-        const payload = items.value.map(normalize_expense);
-
-        emit('save', {
+        validateAll();
+        reset();
+        emit('save', buildExpenseSavePayload({
             pay_period_no: props.pay_period_no,
-            pay_year: props.pay_year,
-            email: props.email,
-            expenses: payload,
-        });
+            pay_year:      props.pay_year,
+            email:         props.email,
+            expenses:      payload(),
+        }));
 
     } catch(err: any) {
         const e = err instanceof ExpensesValidationError
-        ? err: new ExpensesValidationError({
-            status_code: 400,
-            message: String(err?.message || err)
-        });
+            ? err
+            : new ExpensesValidationError({
+                status_code: 400,
+                message: String(err?.message || err)
+            });
         emit('error', e);
     }
 };
 
-const on_form_submit = async () => {
-    triedSubmit.value = true;
-    const ok = await formRef.value?.validate(true);
-    if(!ok) return;
-    add_draft_as_item();
+const onFormSubmit = async () => {
+    try {
+        await validateAnd(async () => {
+            addFromDraft();
+            reset();
+        });
+    } catch (err: any) {
+        const e = err instanceof ExpensesValidationError
+            ? err
+            : new ExpensesValidationError({
+                status_code: 400,
+                message: String(err?.message || err)
+            });
+        emit('error', e);
+    }
 };
 
-const on_close = () => emit('close');
-
-//icons managament 
-type ExpensesType = 'MILEAGE' | 'EXPENSES' | 'PER_DIEM' | 'PRIME_GARDE' | string;
-const normType = (type: unknown) => String(type ?? '').trim().toUpperCase();
-const expenseTypeIcon = (type: ExpensesType) => {
-    const t = normType(type);
-    const map: Record<string, string> = {
-        MILEAGE:     'time_to_leave',
-        EXPENSES:    'receipt_long',
-        PER_DIEM:    'hotel',
-        PRIME_GARDE: 'admin_panel_settings',
-    };
-    return map[String(t)] ?? 'help_outline';
-};
+const onClose = () => emit('close');
 
 </script>
 
 <template>
-    <div >
+    <div>
         <!-- header (title with totals)-->
         <q-item class="row justify-between">
             <q-item-label header class="text-h6 col-auto"> 
@@ -165,243 +121,43 @@ const expenseTypeIcon = (type: ExpensesType) => {
             <q-badge lines="2" class="q-pa-sm q-px-md" :label="$t('timesheet.expense.total_mileage') + ': ' + totals.mileage.toFixed(1)"/>
         </q-item-section>
         </q-item>
-        <!-- liste des dépenses pré existantes -->
-        <q-list 
-            padding 
-            bordered
-            class="rounded-borders"
-        >
-            <q-item-label v-if="items.length === 0" class="text-italic q-px-sm">
-                {{ $t('timesheet.expense.empty_list') }}
-            </q-item-label>
-            <q-item
-                style="border: solid 1px lightgrey; border-radius: 7px;"
-                v-for="(expense, index) in items" :key="index"
-                class="q-my-xs shadow-1"
-            >
-                <!-- avatar type icon section -->
-                <q-item-section avatar>
-                    <q-icon :name="expenseTypeIcon(expense.type)" color="primary"/>
-                </q-item-section>
-
-                <!-- amount or mileage section -->
-                <q-item-section top>
-                    <q-item-label v-if="String(expense.type).trim().toUpperCase() === 'MILEAGE'">
-                        {{ expense.mileage?.toFixed(1) }} km
-                    </q-item-label>
-                    <q-item-label v-else>
-                        {{ expense.amount?.toFixed(2) }} $
-                    </q-item-label>
-
-                    <!-- date label -->
-                    <q-item-label caption lines="2">
-                            {{ $d(new Date(expense.date + 'T00:00:00'), { year:'numeric', month:'short', day: 'numeric', weekday: 'short'}) }}
-                    </q-item-label>
-                </q-item-section>
-
-                <!-- attachment file icon -->
-                <q-item-section side>
-                    <q-btn
-                        push   
-                        dense
-                        size="md"
-                        color="primary"
-                        class="q-mx-lg"
-                        icon="attach_file"
-                    />
-                </q-item-section>
-
-                <!-- comment section -->
-                <q-item-section top>
-                    <q-item-label lines="1">
-                        {{ $t('timesheet.expense.employee_comment') }}
-                    </q-item-label>
-                    <q-item-label caption lines="2">
-                        {{ expense.comment }}
-                    </q-item-label>
-                </q-item-section>
-
-                <!-- supervisor comment section -->
-                <q-item-section top>
-                    <q-item-label lines="1">
-                        {{ $t('timesheet.expense.supervisor_comment') }}
-                    </q-item-label>
-                    <q-item-label v-if="expense.supervisor_comment" caption lines="2">
-                        {{ expense.supervisor_comment }}    
-                    </q-item-label>
-                </q-item-section>    
-
-                <!-- delete btn -->
-                <q-item-section side>
-                    <q-btn
-                        v-if="!is_readonly"
-                        push
-                        dense
-                        size="xs"
-                        color="negative"
-                        icon="close"
-                        @click="remove_item_at(index)"
-                    />
-                </q-item-section>
-            </q-item>
-        </q-list>
-
-        <q-form 
-            ref="formRef"
-            flat 
-            v-if="!is_readonly"
-            @submit.prevent="on_form_submit"
-        >
-            <div class="text-subtitle2 q-py-sm">
-                {{ $t('timesheet.expense.add_expense')}}
-            </div>
-            <div class="row justify-between">
-
-                <!-- date selection input -->
-                <q-input
-                    v-model="draft.date"
-                    type="date"
-                    dense
-                    filled
-                    class="col- q-px-xs"
-                    color="primary"
-                    :label="$t('timesheet.expense.date')"
-                    clearable
-                >
-                </q-input>
-
-                <!-- expenses type selection -->
-                <q-select
-                    v-model="draft.type"
-                    :options="type_options"
-                    :option-label="opt => $t(`timesheet.expense.types.${opt.label}`)"
-                    filled
-                    dense
-                    class="col-auto q-px-xs"
-                    color="primary"
-                    emit-value
-                    map-options
-                    :label="$t('timesheet.expense.type')"
-                    :rules="[ val => !! val || $t('timesheet.expense.errors.type_required')]"
-                    @update:model-value="val => set_draft_type(val as ExpenseType)"
-                />
-                <!-- amount input -->
-                <template v-if="showAmount">
-                    <q-input
-                        key="amount"
-                        v-model.number="draft.amount"
-                        filled
-                        input-class="text-right"
-                        dense
-                        clearable
-                        color="primary"
-                        class="col-auto q-px-xs"
-                        :label="$t('timesheet.expense.amount')"
-                        suffix="$"
-                        lazy-rules="ondemand"
-                        :rules="[ 
-                            value => (value !== undefined && value !== null && value !== '') 
-                            || $t('timesheet.expense.errors.amount_required_for_type')
-                        ]"
-                    />
-                </template>
-
-                <!-- mileage input -->
-                <template v-else>
-                    <q-input
-                        key="mileage"
-                        v-model.number="draft.mileage"
-                        filled
-                        input-class="text-right"
-                        dense
-                        clearable
-                        color="primary"
-                        class="col-auto q-px-xs"
-                        :label="$t('timesheet.expense.mileage')"
-                        suffix="km"
-                        lazy-rules="ondemand"
-                        :rules="[
-                            value => (value !== undefined && value !== null && value !== '')
-                            || $t('timesheet.expense.errors.mileage_required_for_type')
-                        ]"
-                    />
-                </template>
-
-                <!-- employee comment input -->
-                <q-input
-                    v-model="draft.comment"
-                    filled
-                    color="primary"
-                    type="text"
-                    class="col q-px-sm"
-                    dense
-                    clearable
-                    :label="$t('timesheet.expense.employee_comment')"
-                    :counter="true"
-                    :maxlength="COMMENT_MAX_LENGTH"
-                    lazy-rules="ondemand"
-                    :rules="[ 
-                        value => (value && String(value).trim().length) || $t('timesheet.expense.errors.comment_required'),
-                        value => String(value || '').length <= COMMENT_MAX_LENGTH || $t('timesheet.expense.errors.comment_too_long')
-                    ]"
-                />
-                <q-btn 
-                    flat
-                    dense
-                    color="primary"
-                    class="q-px-sm row"
-                >
-                    <div class="row column">
-                        <q-input
-                            v-model="draft.comment"
-                            type="text"
-                            readonly
-                            filled
-                            class="col-auto justify-end"
-                        >
-                            <q-icon
-                                name="attach_file"
-                                size="sm"
-                                class="col-auto justify-start"
-                            />
-                        </q-input>
-
-                    </div>
-                </q-btn>
-                
-                <!-- add btn section -->
-                <div>
-                    <q-btn
-                        push
-                        dense
-                        color="primary"
-                        icon="add"
-                        size="sm"
-                        class="q-mt-sm q-ml-sm"
-                        type="submit"
-                    />                
-                </div>
-            </div>
-            
-        </q-form>
+        <ExpenseList
+            :items="items"
+            :is_readonly="is_readonly"
+            @remove="removeAt"
+        />
+        <ExpenseForm
+            v-model:draft="draft"
+            v-model:files="files"
+            v-model:date-picker-open="is_open_date_picker"
+            :type_options="type_options"
+            :show_amount="showAmount"
+            :is_readonly="is_readonly"
+            :rules="rules"
+            :comment_max_length="COMMENT_MAX_LENGTH"
+            :set-type="setType"
+            @submit="onFormSubmit"
+        />
         
         <q-separator spaced/>
         
         <div class="row col-auto justify-end">
             <!-- close btn -->
             <q-btn
-            flat
+                flat
+                class="q-mr-sm"
                 color="primary"
                 :label="$t('timesheet.cancel_button')"
-                @click="on_close"
+                @click="onClose"
             />
             <!-- save btn -->
             <q-btn
                 color="primary"
                 unelevated
+                push
                 :disable="is_readonly || items.length === 0"
                 :label="$t('timesheet.save_button')"
-                @click="on_save"
+                @click="onSave"
             />
         </div>
     </div>
diff --git a/src/modules/timesheets/components/shift/timesheet-details-shifts-row-header.vue b/src/modules/timesheets/components/shift/detailed-shift-list-header.vue
similarity index 100%
rename from src/modules/timesheets/components/shift/timesheet-details-shifts-row-header.vue
rename to src/modules/timesheets/components/shift/detailed-shift-list-header.vue
diff --git a/src/modules/timesheets/components/shift/timesheet-details-shifts-row.vue b/src/modules/timesheets/components/shift/detailed-shift-list-row.vue
similarity index 92%
rename from src/modules/timesheets/components/shift/timesheet-details-shifts-row.vue
rename to src/modules/timesheets/components/shift/detailed-shift-list-row.vue
index 5058fb9..62586f8 100644
--- a/src/modules/timesheets/components/shift/timesheet-details-shifts-row.vue
+++ b/src/modules/timesheets/components/shift/detailed-shift-list-row.vue
@@ -1,6 +1,6 @@
 <script setup lang="ts">
-import type { Shift } from 'src/modules/timesheets/types/timesheet-shift-interface';
 import { computed } from 'vue';
+import type { Shift } from '../../types/shift.interfaces';
 
 /* eslint-disable */
     const props = defineProps<{
@@ -52,7 +52,7 @@ const on_click_delete  = () => emit('request-delete', { shift: props.shift });
     <q-card-section 
         horizontal
         class="q-pa-none text-uppercase text-center items-center rounded-10"
-        :class="props.shift.type === '' ? '': 'cursor-pointer'"
+        :class="props.shift.type"
         style="line-height: 1;"
         @click.stop="on_click_edit(props.shift.type)"
     >
@@ -79,7 +79,7 @@ const on_click_delete  = () => emit('request-delete', { shift: props.shift });
                 :key="index"
             > 
                 <q-icon
-                    v-if="props.shift.type !== ''"
+                    v-if="props.shift.type"
                     name="double_arrow"
                     :color="icon_data.color"
                     size="24px"
@@ -105,7 +105,7 @@ const on_click_delete  = () => emit('request-delete', { shift: props.shift });
         >
             <!-- comment btn -->
             <q-icon
-                v-if="props.shift.type !== ''"
+                v-if="props.shift.type"
                 :name="comment_icon"
                 :color="comment_color"
                 class="q-pa-none q-mx-xs"
@@ -113,7 +113,7 @@ const on_click_delete  = () => emit('request-delete', { shift: props.shift });
             />
             <!-- expenses btn -->
             <q-btn
-                v-if="props.shift.type !== ''"
+                v-if="props.shift.type"
                 flat 
                 dense
                 color='grey-8'
@@ -122,7 +122,7 @@ const on_click_delete  = () => emit('request-delete', { shift: props.shift });
             /> 
             <!-- delete btn -->
             <q-btn
-                v-if="props.shift.type !== ''"
+                v-if="props.shift.type"
                 push
                 dense
                 size="sm"
diff --git a/src/modules/timesheets/components/shift/timesheet-details-shifts.vue b/src/modules/timesheets/components/shift/detailed-shift-list.vue
similarity index 85%
rename from src/modules/timesheets/components/shift/timesheet-details-shifts.vue
rename to src/modules/timesheets/components/shift/detailed-shift-list.vue
index a2903dd..340478e 100644
--- a/src/modules/timesheets/components/shift/timesheet-details-shifts.vue
+++ b/src/modules/timesheets/components/shift/detailed-shift-list.vue
@@ -1,10 +1,11 @@
 <script setup lang="ts">
-import { default_shift, type Shift } from 'src/modules/timesheets/types/timesheet-shift-interface';
 import type { PayPeriod } from 'src/modules/shared/types/pay-period-interface';
-import type { TimesheetPayPeriodDetailsOverview } from '../../types/timesheet-pay-period-details-overview-interface';
-import TimesheetDetailsShiftsRowHeader from './timesheet-details-shifts-row-header.vue';
-import TimesheetDetailsShiftsRow from './timesheet-details-shifts-row.vue';
+import detailedShiftListHeader from './detailed-shift-list-header.vue';
+import detailedShiftListRow from './detailed-shift-list-row.vue';
 import { date } from 'quasar';
+import type { TimesheetPayPeriodDetailsOverview } from '../../types/timesheet.interfaces';
+import type { Shift } from '../../types/shift.interfaces';
+import { default_shift } from '../../types/shift.defaults';
 
     const props = defineProps<{
         rawData: TimesheetPayPeriodDetailsOverview;
@@ -72,13 +73,13 @@ import { date } from 'quasar';
 
             <!-- List of shifts column -->
             <q-card-section class="col q-pa-none">
-                <TimesheetDetailsShiftsRowHeader />
-                <TimesheetDetailsShiftsRow
+                <detailedShiftListHeader />
+                <detailedShiftListRow
                     v-for="shift, shift_index in shifts_or_placeholder(day.shifts)"
                     :key="shift_index" 
                     :shift="shift"
-                    @request-edit="  ({ shift })           => on_request_edit(to_iso_date(day.short_date), shift )"
-                    @request-delete="({ shift })           => on_request_delete(to_iso_date(day.short_date), shift )"
+                    @request-edit="  ({ shift }) => on_request_edit(to_iso_date(day.short_date), shift )"
+                    @request-delete="({ shift }) => on_request_delete(to_iso_date(day.short_date), shift )"
                 />
             </q-card-section>
             <!-- add shift btn column -->
diff --git a/src/modules/timesheets/components/shift/shift-crud-dialog.vue b/src/modules/timesheets/components/shift/shift-crud-dialog.vue
index df27201..24dbce4 100644
--- a/src/modules/timesheets/components/shift/shift-crud-dialog.vue
+++ b/src/modules/timesheets/components/shift/shift-crud-dialog.vue
@@ -1,10 +1,11 @@
 <script setup lang="ts">
 
 import { computed, ref, watch } from 'vue';
-import { upsert_shifts_by_date, type UpsertShiftsBody, type ShiftPayload } from '../../composables/use-shift-api';
 import { useI18n } from 'vue-i18n';
+import { SHIFT_KEY, type ShiftKey, type ShiftPayload, type ShiftSelectOption } from '../../types/shift.types';
+import type { UpsertShiftsBody }   from '../../types/shift.interfaces';
+import { upsertShiftsByDate } from '../../composables/api/use-shift-api';
  /* eslint-disable */
-type Option   = { value: string; label: string };
 
 const { t } = useI18n();
 
@@ -12,27 +13,30 @@ const props = defineProps<{
     mode:          'create' | 'edit' | 'delete';
     dateIso:       string;
     initialShift?: ShiftPayload | null;
-    shiftOptions:  Option[];
+    shiftOptions:  ShiftSelectOption[];
     email:         string;
 }>();
 
 const emit = defineEmits<{
-    (e: 'close' ): void;
-    (e: 'saved'): void;
+    'close': []
+    'saved': []
 }>();
 
 const isSubmitting = ref(false);
 const errorBanner  = ref<string | null>(null);
 const conflicts    = ref<Array<{start_time: string; end_time: string; type: string}>>([]);
 
-const opened    = defineModel<boolean>(             { default: false });
-const startTime = defineModel<string> ('startTime', { default: ''    });
-const endTime   = defineModel<string> ('endTime'  , { default: ''    });
-const type      = defineModel<string> ('type'     , { default: ''    });
-const isRemote  = defineModel<boolean>('isRemote' , { default: false });
-const comment   = defineModel<string> ('comment'  , { default: ''    });
+const opened    = defineModel<boolean>       (             { default: false });
+const startTime = defineModel<string>        ('startTime', { default: ''    });
+const endTime   = defineModel<string>        ('endTime'  , { default: ''    });
+const type      = defineModel<ShiftKey | ''> ('type'     , { default: ''    });
+const isRemote  = defineModel<boolean>       ('isRemote' , { default: false });
+const comment   = defineModel<string>        ('comment'  , { default: ''    });
+
+const isShiftKey = (val: unknown): val is ShiftKey => SHIFT_KEY.includes(val as ShiftKey);
 
 const buildNewShiftPayload = (): ShiftPayload => {
+    if(!isShiftKey(type.value)) throw new Error('Invalid shift type');
     const trimmed = (comment.value ??  '').trim();
     return {
         start_time: startTime.value,
@@ -59,7 +63,7 @@ const onSubmit = async () => {
             if (!props.initialShift) throw new Error('Missing initial Shift for delete.');
             body = { old_shift: props.initialShift };
         }
-        await upsert_shifts_by_date(props.email, props.dateIso, body);
+        await upsertShiftsByDate(props.email, props.dateIso, body);
         opened.value = false;
         emit('saved');
     } catch (error: any) {
@@ -106,8 +110,8 @@ const hydrateFromProps = () => {
 const canSubmit = computed(() => 
     props.mode === 'delete' ||
     (startTime.value.trim().length === 5 &&
-       endTime.value.trim().length === 5 &&
-          type.value.trim().length     > 0)
+     endTime.value.trim().length   === 5 &&
+     isShiftKey(type.value))
 );
 
 watch(
@@ -120,16 +124,17 @@ watch(
 </script> 
  
  <!-- create/edit/delete shifts dialog -->
-  <template>
-    <q-dialog 
-        v-model="opened"
-        persistent 
-        transition-show="fade" 
-        transition-hide="fade"
-    >
+<template>
+    <q-dialog   v-model="opened"
+                persistent 
+                transition-show="fade" 
+                transition-hide="fade">
+
         <q-card class="q-pa-md">
             <div class="row items-center q-mb-sm">
-                <q-icon name="schedule" size="24px" class="q-mr-sm"/>
+                <q-icon name="schedule" 
+                        size="24px"
+                        class="q-mr-sm"/>
                 <div class="text-h6">
                     {{ 
                         props.mode === 'create' 
@@ -140,7 +145,9 @@ watch(
                     }}
                 </div>
                 <q-space/>
-                <q-badge outline color="primary">{{ props.dateIso }}</q-badge>
+                <q-badge outline color="primary">
+                    {{ props.dateIso }}
+                </q-badge>
             </div>
             
             <q-separator spaced/>
@@ -227,15 +234,13 @@ watch(
                     :disable="!canSubmit"
                     @click="onSubmit"
                 />
-                <q-btn
-                    v-else
-                    color="primary" 
-                    icon="save_alt" 
-                    :label="$t('timesheet.save_button')"
-                    :loading="isSubmitting"
-                    :disable="!canSubmit"
-                    @click="onSubmit"
-                />
+                <q-btn  v-else
+                        color="primary" 
+                        icon="save_alt" 
+                        :label="$t('timesheet.save_button')"
+                        :loading="isSubmitting"
+                        :disable="!canSubmit"
+                        @click="onSubmit"/>
             </div>
         </q-card>
     </q-dialog>
diff --git a/src/modules/timesheets/components/shift/shifts-legend.vue b/src/modules/timesheets/components/shift/shifts-legend.vue
index 08a568f..035d78d 100644
--- a/src/modules/timesheets/components/shift/shifts-legend.vue
+++ b/src/modules/timesheets/components/shift/shifts-legend.vue
@@ -1,17 +1,11 @@
 <script setup lang="ts">
 import { computed } from 'vue';
 import { useI18n } from 'vue-i18n';
+import type { ShiftLegendItem } from '../../types/shift.types';
 
 const { t } = useI18n();
 const props = defineProps<{ isLoading: boolean; }>();
 
-type ShiftLegendItem = {
-    type: 'REGULAR'|'EVENING'|'EMERGENCY'|'OVERTIME'|'VACATION'|'HOLIDAY'|'SICK';
-    color: string;
-    label_key: string;
-    text_color?: string;
-};
-
 const legend: ShiftLegendItem[] = [
     {type:'REGULAR'  , color: 'secondary', label_key: 'timesheet.shift.types.REGULAR', text_color: 'grey-8'},
     {type:'EVENING'  , color: 'warning'  , label_key: 'timesheet.shift.types.EVENING'},
diff --git a/src/modules/timesheets/components/timesheet/timesheet-save-payload.vue b/src/modules/timesheets/components/timesheet/timesheet-save-payload.vue
index 1308ba4..9cc7c8b 100644
--- a/src/modules/timesheets/components/timesheet/timesheet-save-payload.vue
+++ b/src/modules/timesheets/components/timesheet/timesheet-save-payload.vue
@@ -1,12 +1,10 @@
 <script setup lang="ts">
-/* eslint-disable */
 import { computed } from 'vue';
-import type { CreateShiftPayload } from '../../types/timesheet-shifts-payload-interface';
-import type { Shift } from '../../types/timesheet-shift-interface';
-
+import type { CreateShiftPayload, Shift } from '../../types/shift.interfaces';
 
+/* eslint-disable */
 const props = defineProps<{
-    rows: Shift[];
+    rows:       Shift[];
     week_dates: string[];
 }>();
 
diff --git a/src/modules/timesheets/composables/use-expense-api.ts b/src/modules/timesheets/composables/api/use-expense-api.ts
similarity index 65%
rename from src/modules/timesheets/composables/use-expense-api.ts
rename to src/modules/timesheets/composables/api/use-expense-api.ts
index e8beb38..899e3d0 100644
--- a/src/modules/timesheets/composables/use-expense-api.ts
+++ b/src/modules/timesheets/composables/api/use-expense-api.ts
@@ -1,56 +1,27 @@
-import { isProxy, toRaw } from "vue";
-import { type ExpenseType, type TimesheetExpense } from "../types/timesheet-expenses-interface";
-import { type PayPeriodExpenses } from "../types/timesheet-expenses-list-interface";
-import { normalize_expense, validate_expense_UI } from "../utils/timesheet-expenses-validators";
 import { api } from "src/boot/axios";
+import { isProxy, toRaw } from "vue";
+import { normalizeExpense, validateExpenseUI } from "../../utils/expenses-validators";
+import type { ExpenseType } from "../../types/expense.types";
+import { ExpensesApiError } from "../../types/expense-validation.interface";
+import type { 
+    ExpensePayload, 
+    PayPeriodExpenses, 
+    TimesheetExpense, 
+    UpsertExpensesBody, 
+    UpsertExpensesResponse 
+} from "../../types/expense.interfaces";
+
 /* eslint-disable */
-export interface ExpensePayload{
-    date:               string;
-    type:               ExpenseType;
-    amount?:            number;
-    mileage?:           number;
-    comment:            string;
-}
-
-export interface UpsertExpensesBody {
-    expenses: ExpensePayload[];
-}
-
-export interface UpsertExpensesResponse {
-    data: PayPeriodExpenses;
-}
-
-export interface ApiErrorPayload {
-    status_code: number;
-    error_code?:  string;
-    message?:    string;
-    context?:    Record<string,unknown>;
-}
-
-export class ExpensesApiError extends Error {
-    status_code: number;
-    error_code?: string;
-    context?:    Record<string, unknown>;
-    constructor(payload: ApiErrorPayload) {
-        super(payload.message || 'Request failed');
-        this.name        = 'ExpensesApiError';
-        this.status_code = payload.status_code;
-
-        if(payload.error_code !== undefined) this.error_code = payload.error_code;
-        if(payload.context    !== undefined) this.context    = payload.context;
-    }
-}
-
-const to_plain = <T extends object>(obj:T): T => {
+const toPlain = <T extends object>(obj:T): T => {
     const raw = isProxy(obj) ? toRaw(obj) : obj;
-    if(typeof (globalThis as any).structuredClone === 'function') {
+    if( typeof (globalThis as any).structuredClone === 'function') {
         return (globalThis as any).structuredClone(raw);
     }
     return JSON.parse(JSON.stringify(raw));
 };
 
-const normalize_payload = (expense: ExpensePayload): ExpensePayload => {
-    const exp = normalize_expense(expense as unknown as TimesheetExpense);
+const normalizePayload = (expense: ExpensePayload): ExpensePayload => {
+    const exp = normalizeExpense(expense as unknown as TimesheetExpense);
     const out: ExpensePayload = {
         date: exp.date,
         type: exp.type as ExpenseType,
@@ -62,7 +33,7 @@ const normalize_payload = (expense: ExpensePayload): ExpensePayload => {
 }
 
 //GET by email, year and period no
-export const get_pay_period_expenses = async (
+export const getPayPeriodExpenses = async (
     email: string,
     pay_year: number,
     pay_period_no: number
@@ -74,7 +45,7 @@ export const get_pay_period_expenses = async (
     try {
         const { data } = await api.get<PayPeriodExpenses>(`/expenses/${encoded_email}/${encoded_year}/${encoded_pay_period_no}`);
 
-        const items = Array.isArray(data.expenses) ? data.expenses.map(normalize_expense) : [];
+        const items = Array.isArray(data.expenses) ? data.expenses.map(normalizeExpense) : [];
         return {
             ...data,
             expenses: items,
@@ -92,7 +63,7 @@ export const get_pay_period_expenses = async (
 };
 
 //PUT by email, year and period no
-export const put_pay_period_expenses = async (
+export const putPayPeriodExpenses = async (
     email: string,
     pay_year: number,
     pay_period_no: number,
@@ -102,12 +73,12 @@ export const put_pay_period_expenses = async (
     const encoded_year  = encodeURIComponent(String(pay_year));
     const encoded_pay_period_no = encodeURIComponent(String(pay_period_no));
 
-    const plain = Array.isArray(expenses) ? expenses.map(to_plain): [];
+    const plain = Array.isArray(expenses) ? expenses.map(toPlain): [];
 
     const normalized: ExpensePayload[] = plain.map((exp) => {
-        const norm = normalize_expense(exp as TimesheetExpense);
-        validate_expense_UI(norm, 'expense_item');        
-        return normalize_payload(norm as unknown as ExpensePayload);
+        const norm = normalizeExpense(exp as TimesheetExpense);
+        validateExpenseUI(norm, 'expense_item');        
+        return normalizePayload(norm as unknown as ExpensePayload);
     });
 
     const body: UpsertExpensesBody = {expenses: normalized};
@@ -120,7 +91,7 @@ export const put_pay_period_expenses = async (
         );
 
         const items = Array.isArray(data?.data?.expenses)
-        ? data.data.expenses.map(normalize_expense)
+        ? data.data.expenses.map(normalizeExpense)
         : [];
         return {
             ...(data?.data ?? {
@@ -145,7 +116,7 @@ export const put_pay_period_expenses = async (
     }
 };
 
-export const post_pay_period_expenses = async (
+export const postPayPeriodExpenses = async (
   email: string,
   pay_year: number,
   pay_period_no: number,
@@ -155,11 +126,11 @@ export const post_pay_period_expenses = async (
   const encoded_year = encodeURIComponent(String(pay_year));
   const encoded_pp = encodeURIComponent(String(pay_period_no));
 
-  const plain = Array.isArray(new_expenses) ? new_expenses.map(to_plain) : [];
+  const plain = Array.isArray(new_expenses) ? new_expenses.map(toPlain) : [];
   const normalized: ExpensePayload[] = plain.map((exp) => {
-    const norm = normalize_expense(exp as TimesheetExpense);
-    validate_expense_UI(norm, 'expense_item');
-    return normalize_payload(norm as unknown as ExpensePayload);
+    const norm = normalizeExpense(exp as TimesheetExpense);
+    validateExpenseUI(norm, 'expense_item');
+    return normalizePayload(norm as unknown as ExpensePayload);
   });
 
   const body: UpsertExpensesBody = { expenses: normalized };
@@ -171,7 +142,7 @@ export const post_pay_period_expenses = async (
       { headers: { 'content-type': 'application/json' } }
     );
     const items = Array.isArray(data?.data?.expenses)
-      ? data.data.expenses.map(normalize_expense)
+      ? data.data.expenses.map(normalizeExpense)
       : [];
     return {
       ...(data?.data ?? {
diff --git a/src/modules/timesheets/composables/use-shift-api.ts b/src/modules/timesheets/composables/api/use-shift-api.ts
similarity index 83%
rename from src/modules/timesheets/composables/use-shift-api.ts
rename to src/modules/timesheets/composables/api/use-shift-api.ts
index 0e172cd..855738b 100644
--- a/src/modules/timesheets/composables/use-shift-api.ts
+++ b/src/modules/timesheets/composables/api/use-shift-api.ts
@@ -1,37 +1,9 @@
 import { api } from "src/boot/axios";
 import { isProxy, toRaw } from "vue";
+import { DATE_FORMAT_PATTERN, TIME_FORMAT_PATTERN } from "../../constants/shift.constants";
+import type { ShiftPayload } from "../../types/shift.types";
+import type { UpsertShiftsBody, UpsertShiftsResponse } from "../../types/shift.interfaces";
 /* eslint-disable */
-export interface ShiftPayload {
-    start_time: string;
-    end_time:   string;
-    type:       string;
-    is_remote:  boolean;
-    comment?:   string;
-}
-
-export interface UpsertShiftsBody {
-    old_shift?: ShiftPayload;
-    new_shift?: ShiftPayload;
-}
-
-export type UpsertAction = 'created' | 'updated' | 'deleted';
-
-export interface DayShift {
-    start_time: string;
-    end_time:   string;
-    type:       string;
-    is_remote:  boolean;
-    comment?:   string | null;
-}
-
-export interface UpsertShiftsResponse {
-    action: UpsertAction;
-    day:    DayShift[];
-}
-
-export const TIME_FORMAT_PATTERN = /^\d{2}:\d{2}$/;
-export const DATE_FORMAT_PATTERN = /^\d{4}-\d{2}-\d{2}$/;
-export const COMMENT_MAX_LENGTH = 512 as const;
 
 //normalize payload to match backend data
 export const normalize_comment = (input?: string): string | undefined => {
@@ -40,14 +12,12 @@ export const normalize_comment = (input?: string): string | undefined => {
     return trimmed.length ? trimmed : undefined;
 }
 
-export const normalize_type = (input: string): string => (input ?? '').trim().toUpperCase();
-
 export const normalize_payload = (payload: ShiftPayload): ShiftPayload => {
     const comment = normalize_comment(payload.comment);
     return {
         start_time: payload.start_time,
         end_time:   payload.end_time,
-        type:       normalize_type(payload.type),
+        type:       payload.type,
         is_remote:  Boolean(payload.is_remote),
         ...(comment !== undefined ? { comment } : {}),
     };
@@ -120,7 +90,7 @@ const validateShift = (payload: ShiftPayload, label: 'old_shift'|'new_shift') =>
     }
 }
 
-export const upsert_shifts_by_date = async (
+export const upsertShiftsByDate = async (
     email: string,
     date: string,
     body: UpsertShiftsBody,
diff --git a/src/modules/timesheets/composables/use-timesheet-api.ts b/src/modules/timesheets/composables/api/use-timesheet-api.ts
similarity index 81%
rename from src/modules/timesheets/composables/use-timesheet-api.ts
rename to src/modules/timesheets/composables/api/use-timesheet-api.ts
index 37c81dc..0b60564 100644
--- a/src/modules/timesheets/composables/use-timesheet-api.ts
+++ b/src/modules/timesheets/composables/api/use-timesheet-api.ts
@@ -1,6 +1,6 @@
 import { useAuthStore } from "src/stores/auth-store";
 import { useTimesheetStore } from "src/stores/timesheet-store"
-
+/* eslint-disable */
 export const useTimesheetApi = () => {
     const timesheet_store = useTimesheetStore();
     const auth_store = useAuthStore();
@@ -34,16 +34,25 @@ export const useTimesheetApi = () => {
             await timesheet_store.getTimesheetsByPayPeriodAndEmail(auth_store.user.email);
         }
     };
-
-    const getCurrentPayPeriod  = async () => fetchPayPeriod(0);
+    
     const getNextPayPeriod     = async () => fetchPayPeriod(1);
     const getPreviousPayPeriod = async () => fetchPayPeriod(-1);
 
+    const getPreviousPeriodForUser = async (_employee_email: string) => {
+        await getPreviousPayPeriod();
+    };
+
+    const getNextPeriodForUser = async (_employee_email: string) => {
+        await getNextPayPeriod();
+    };
+
     return { 
         getTimesheetsByDate,
         fetchPayPeriod,
-        getCurrentPayPeriod,
+        // getCurrentPayPeriod,
         getNextPayPeriod,
         getPreviousPayPeriod,
+        getPreviousPeriodForUser,
+        getNextPeriodForUser,
     };
 };
\ No newline at end of file
diff --git a/src/modules/timesheets/composables/use-expense-draft.ts b/src/modules/timesheets/composables/use-expense-draft.ts
new file mode 100644
index 0000000..182a5d3
--- /dev/null
+++ b/src/modules/timesheets/composables/use-expense-draft.ts
@@ -0,0 +1,36 @@
+import { ref, computed } from "vue";
+import type { TimesheetExpense } from "../types/expense.interfaces";
+import type { ExpenseType } from "../types/expense.types";
+
+export const useExpenseDraft = (initial?: Partial<TimesheetExpense>) => {
+    const DEFAULT_TYPE: ExpenseType = 'EXPENSES';
+
+    const draft = ref<Partial<TimesheetExpense>>({
+        date: '',
+        type: DEFAULT_TYPE,
+        comment: '',
+        ...(initial ?? {}),
+    });
+
+    const reset = () => {
+        draft.value = {
+            date: '',
+            type: DEFAULT_TYPE,
+            comment: '',
+        }
+    }
+
+    const setType = (value: ExpenseType) => {
+        draft.value.type = value;
+        if(value === 'MILEAGE') {
+            delete draft.value.amount;
+        } else {
+            delete draft.value.mileage;
+        }
+    };
+
+    const showMileage = computed(()=> (draft.value.type as string) === 'MILEAGE');
+    const showAmount  = computed(()=> !showMileage.value);
+
+    return { draft, setType, reset, showMileage, showAmount };
+}
\ No newline at end of file
diff --git a/src/modules/timesheets/composables/use-expense-form.ts b/src/modules/timesheets/composables/use-expense-form.ts
new file mode 100644
index 0000000..1947693
--- /dev/null
+++ b/src/modules/timesheets/composables/use-expense-form.ts
@@ -0,0 +1,21 @@
+import { ref } from "vue";
+import type { QForm } from "quasar"
+
+
+export const useExpenseForm = () => {
+    const formRef     = ref<QForm | null>(null);
+    const triedSubmit = ref(false);
+
+    const validateAnd = async (fn: ()=> void | Promise<void>) => {
+        triedSubmit.value = true;
+        const ok = await formRef.value?.validate(true);
+        if(!ok) return false;
+        await fn();
+        return true;
+    };
+
+    return { 
+        formRef,
+        validateAnd,
+    };
+}
\ No newline at end of file
diff --git a/src/modules/timesheets/composables/use-expense-items.ts b/src/modules/timesheets/composables/use-expense-items.ts
new file mode 100644
index 0000000..5b90aa8
--- /dev/null
+++ b/src/modules/timesheets/composables/use-expense-items.ts
@@ -0,0 +1,55 @@
+import { ref, type Ref } from "vue";
+import { normalizeExpense, validateExpenseUI } from "../utils/expenses-validators";
+import { normExpenseType } from "../utils/expense.util";
+import type { TimesheetExpense } from "../types/expense.interfaces";
+
+type UseExpenseItemsParams = {
+    initial_expenses?: TimesheetExpense[] | null | undefined;
+    draft: Ref<Partial<TimesheetExpense>>;
+    is_approved: Ref<boolean> | boolean;
+};
+export const useExpenseItems = ({ 
+    initial_expenses,
+    draft,
+    is_approved
+}: UseExpenseItemsParams) => {
+    const items = ref<TimesheetExpense[]>(
+        Array.isArray(initial_expenses) ? initial_expenses.map(normalizeExpense) : []
+    );
+
+    const addFromDraft = () => {
+        const candidate: TimesheetExpense = normalizeExpense({
+            date: draft.value.date,
+            type: normExpenseType(draft.value.type),
+            ...(typeof draft.value.amount  === 'number' ? { amount: draft.value.amount   }: {}),
+            ...(typeof draft.value.mileage === 'number' ? { mileage: draft.value.mileage }: {}),
+            comment: String(draft.value.comment ?? '').trim(),
+        } as TimesheetExpense);
+
+        validateExpenseUI(candidate, 'expense_draft');
+        items.value = [ ...items.value, candidate];
+    };
+
+    const removeAt = (index: number) => {
+        const locked = typeof is_approved === 'boolean' ? is_approved : is_approved.value;
+        if(locked) return;
+        if(index < 0 || index >= items.value.length) return;
+        items.value = items.value.filter((_,i)=> i !== index);
+    };
+
+    const validateAll = () => {
+        for (const expense of items.value) {
+            validateExpenseUI(expense, 'expense_item');
+        }
+    };
+
+    const payload = () => items.value.map(normalizeExpense);
+
+    return {
+        items,
+        addFromDraft,
+        removeAt,
+        validateAll,
+        payload,
+    };
+};
diff --git a/src/modules/timesheets/constants/expense.constants.ts b/src/modules/timesheets/constants/expense.constants.ts
new file mode 100644
index 0000000..14ad95b
--- /dev/null
+++ b/src/modules/timesheets/constants/expense.constants.ts
@@ -0,0 +1,3 @@
+export const COMMENT_MAX_LENGTH = 280;
+
+export const DATE_FORMAT_PATTERN = /^\d{4}-\d{2}-\d{2}$/;
\ No newline at end of file
diff --git a/src/modules/timesheets/constants/shift.constants.ts b/src/modules/timesheets/constants/shift.constants.ts
new file mode 100644
index 0000000..80f821b
--- /dev/null
+++ b/src/modules/timesheets/constants/shift.constants.ts
@@ -0,0 +1,2 @@
+export const TIME_FORMAT_PATTERN = /^\d{2}:\d{2}$/;
+export const DATE_FORMAT_PATTERN = /^\d{4}-\d{2}-\d{2}$/;
\ No newline at end of file
diff --git a/src/modules/timesheets/pages/timesheet-details-overview.vue b/src/modules/timesheets/pages/timesheet-details-overview.vue
index d183998..6f51407 100644
--- a/src/modules/timesheets/pages/timesheet-details-overview.vue
+++ b/src/modules/timesheets/pages/timesheet-details-overview.vue
@@ -1,193 +1,76 @@
 <script setup lang="ts">
-import { useTimesheetStore } from 'src/stores/timesheet-store';
-import { useAuthStore } from 'src/stores/auth-store';
-import { useTimesheetApi } from '../composables/use-timesheet-api';
-import { useI18n } from 'vue-i18n';
-import { computed, onMounted, ref } from 'vue';
 import { date } from 'quasar';
-import TimesheetNavigation from '../components/timesheet/timesheet-navigation.vue';
-import ShiftsLegend from '../components/shift/shifts-legend.vue';
-import TimesheetDetailsShifts from '../components/shift/timesheet-details-shifts.vue';
-import { type ShiftPayload } from '../composables/use-shift-api';
-import { ExpensesApiError, get_pay_period_expenses, put_pay_period_expenses } from '../composables/use-expense-api';
-import type { PayPeriodExpenses } from '../types/timesheet-expenses-list-interface';
-import type { TimesheetExpense } from '../types/timesheet-expenses-interface';
-import TimesheetDetailsExpenses from '../components/expenses/timesheet-details-expenses.vue';
-import ShiftCrudDialog from '../components/shift/shift-crud-dialog.vue';
+import { computed, onMounted }    from 'vue';
+import { useI18n }                from 'vue-i18n';
+import { useAuthStore }           from 'src/stores/auth-store';
+import { useExpensesStore }       from 'src/stores/expense-store';
+import { useShiftStore }          from 'src/stores/shift-store';
+import { useTimesheetStore }      from 'src/stores/timesheet-store';
+import { useTimesheetApi }        from '../composables/api/use-timesheet-api';
+import { buildShiftOptions }      from '../utils/shift.util';
+import { formatPayPeriodLabel }   from '../utils/timesheet-format.util';
+import   TimesheetNavigation      from '../components/timesheet/timesheet-navigation.vue';
+import   ShiftsLegend             from '../components/shift/shifts-legend.vue';
+import   ShiftCrudDialog          from '../components/shift/shift-crud-dialog.vue';
+import   TimesheetDetailsExpenses from '../components/expenses/timesheet-details-expenses.vue';
+import { SHIFT_KEY }              from '../types/shift.types';
+import type { TimesheetExpense }  from '../types/expense.interfaces';
+import DetailedShiftList from '../components/shift/detailed-shift-list.vue';
+/* eslint-disable */
 
- /* eslint-disable */
-const { locale, t } = useI18n();
+//------------------- stores ------------------- 
+const { locale, t }   = useI18n();
+const auth_store      = useAuthStore();
+const expenses_store  = useExpensesStore();
+const shift_store     = useShiftStore();
 const timesheet_store = useTimesheetStore();
-const auth_store = useAuthStore();
-const timesheet_api = useTimesheetApi();
+const timesheet_api   = useTimesheetApi();
 
-//expenses refs
-const show_expenses_dialog = ref(false);
-const is_loading_expenses  = ref(false);
-const expenses_data        = ref<PayPeriodExpenses | null>(null);
-
-const notify_error = (err: number) => {
-    const e = err as any;
-    expenses_error.value = (e instanceof ExpensesApiError && t(e.message)) || e?.message || 'Unknown error';
-};
-
-const open_expenses_dialog = async () => {
-    show_expenses_dialog.value = true;
-    is_loading_expenses.value  = true;
-    expenses_error.value         = null;
-
-    try {
-        const data = await get_pay_period_expenses(
-            auth_store.user.email,
-            timesheet_store.current_pay_period.pay_year,
-            timesheet_store.current_pay_period.pay_period_no,
-        );
-    } catch(err) {
-        notify_error(err as any);
-        expenses_data.value = {
-            pay_period_no:  timesheet_store.current_pay_period.pay_period_no,
-            pay_year:       timesheet_store.current_pay_period.pay_year,
-            employee_email: auth_store.user.email,
-            is_approved:    false,
-            expenses:       [],
-            totals:         {amount:0, mileage:0},
-        };
-    } finally {
-        is_loading_expenses.value = false;
-    }
-};
-
-const on_save_expenses = async (payload: {
-    pay_period_no: number;
-    pay_year:      number;
-    email:         string;
-    expenses:      TimesheetExpense[];
-}) => {
-    is_loading_expenses.value = true;
-    expenses_error.value = null;
-
-    try{
-        const updated = await put_pay_period_expenses(
-            payload.email,
-            payload.pay_year,
-            payload.pay_period_no,
-            payload.expenses
-        );
-        expenses_data.value = updated;
-
-        await timesheet_store.getTimesheetsByPayPeriodAndEmail(auth_store.user.email);
-
-        show_expenses_dialog.value = false;
-    } catch(err) {
-        notify_error(err as any);
-    } finally {
-        is_loading_expenses.value = false;
-    }
-};
-
-const on_close_expenses = () => {
-    show_expenses_dialog.value = false;
-}
-
-const date_options: Intl.DateTimeFormatOptions = {
-    day:   'numeric',
-    month: 'long',
-    year:  'numeric',
-};
-
-const pay_period_label = computed(() => {
-    const label = timesheet_store.current_pay_period?.label ?? '';
-    const dates = label.split('.');
-    if ( dates.length < 2 ) {
-        return { start_date: '—', end_date:'—' }
-    }
-    const start_date = new Intl.DateTimeFormat(locale.value, date_options).format(date.extractDate(dates[0] as string, 'YYYY-MM-DD'));
-    const end_date = new Intl.DateTimeFormat(locale.value, date_options).format(date.extractDate(dates[1] as string, 'YYYY-MM-DD'));
-    return { start_date, end_date };
+//------------------- expenses -------------------
+const openExpensesDialog = () => expenses_store.openDialog({
+    email:         auth_store.user.email,
+    pay_year:      timesheet_store.current_pay_period.pay_year,
+    pay_period_no: timesheet_store.current_pay_period.pay_period_no,
+    t,
 });
 
-const is_calendar_limit = computed( () => {
-    return  timesheet_store.current_pay_period.pay_year === 2024 && 
-            timesheet_store.current_pay_period.pay_period_no <= 1;
-});
+const onSaveExpenses = async ( payload: { email: string; pay_year: number; pay_period_no: number; expenses: TimesheetExpense[] }) => {
+    await expenses_store.saveExpenses({...payload, t});
+    await timesheet_store.refreshCurrentPeriodForUser(auth_store.user.email);
+};
 
-const SHIFT_KEY = ['REGULAR', 'EVENING', 'EMERGENCY', 'HOLIDAY', 'VACATION', 'SICK'] as const;
-const shift_options = computed(()=> {
-    void locale.value;
-    return SHIFT_KEY.map(key => ({ value: key, label: t(`timesheet.shift_types.${key}`)}))
-});
+const onCloseExpenses = () => expenses_store.closeDialog();
 
+//------------------- pay-period format label -------------------
+const date_options: Intl.DateTimeFormatOptions = { day: 'numeric', month: 'long', year:  'numeric' };
 
+const pay_period_label = computed(() => formatPayPeriodLabel(
+        timesheet_store.current_pay_period?.label,
+        locale.value,
+        date.extractDate,
+        date_options
+    )
+);
+
+//------------------- q-select Shift options -------------------
+const shift_options = computed(() => buildShiftOptions(SHIFT_KEY, t));
+
+//------------------- navigation by date -------------------
 const onDateSelected = async (date_string: string) => {
-    await timesheet_api.getTimesheetsByDate(date_string);
+    await timesheet_store.loadByIsoDate(date_string, auth_store.user.email);
 };
 
-const loadByDate = async (isoDate: string) => {
-    await timesheet_store.getPayPeriodByDate(isoDate);
-    await timesheet_store.getTimesheetsByPayPeriodAndEmail(auth_store.user.email);
-};
-
-onMounted( async () => {
-    await loadByDate(date.formatDate(new Date(), 'YYYY-MM-DD' ));
+onMounted(async () => {
+    await timesheet_store.loadToday(auth_store.user.email);
 });
 
+// ------------------- shifts -------------------
+const onRequestAdd    =       ({ date        }: { date: string }) => shift_store.openCreate(date);
+const onRequestEdit   =       ({ date, shift }: { date: string; shift: any }) => shift_store.openEdit(date, shift);
+const onRequestDelete = async ({ date, shift }: { date: string; shift: any }) => shift_store.openDelete(date, shift);
 const onShiftSaved = async () => {
-    await timesheet_store.getTimesheetsByPayPeriodAndEmail(auth_store.user.email);
-}
-
-type FormMode = 'create' | 'edit' | 'delete';
-
-const is_dialog_open = ref<boolean>(false);
-const form_mode      = ref<FormMode>('create');
-const selected_date  = ref<string>('');
-const old_shift_ref  = ref<ShiftPayload | undefined>(undefined);
-
-const open_create_dialog = (iso_date: string) => {
-    form_mode.value      = 'create';
-    selected_date.value  = iso_date;
-    old_shift_ref.value  = undefined;
-    is_dialog_open.value = true;
+    await timesheet_store.refreshCurrentPeriodForUser(auth_store.user.email);
 };
-
-const open_edit_dialog = (iso_date: string, shift: any) => {
-    form_mode.value      = 'edit';
-    selected_date.value  = iso_date;
-    is_dialog_open.value = true;
-    old_shift_ref.value  = {
-        start_time:   shift.start_time,
-        end_time:     shift.end_time,
-        type:         shift.type,
-        is_remote:  !!shift.is_remote,
-        ...(shift.comment ? { comment: String(shift.comment)} : {}),
-    };
-};
-
-const open_delete_dialog = (iso_date: string, shift: any) => {
-    form_mode.value = 'delete';
-    selected_date.value = iso_date;
-        old_shift_ref.value  = {
-        start_time:    shift.start_time,
-        end_time:      shift.end_time,
-        type:          shift.type,
-        is_remote:   !!shift.is_remote,
-        ...(shift.comment ? { comment: String(shift.comment)} : {}),
-    };
-    is_dialog_open.value = true;
-};
-
-
-
-
-const expenses_error = ref<string|null>(null);
-
-const close_dialog = () => { 
-    expenses_error.value = null;
-    is_dialog_open.value = false;
- };
-
-const on_request_add    =       ({ date        }: { date: string }) => open_create_dialog(date);
-const on_request_edit   =       ({ date, shift }: { date: string; shift: any }) => open_edit_dialog(date, shift);
-const on_request_delete = async ({ date, shift }: { date: string; shift: any }) => open_delete_dialog(date, shift);
 </script>
 
 
@@ -226,16 +109,16 @@ const on_request_delete = async ({ date, shift }: { date: string; shift: any })
                         unelevated
                         icon="receipt_long"
                         :label="$t('timesheet.expense.open_btn')"
-                        @click="open_expenses_dialog"
+                        @click="openExpensesDialog"
                     />
                 </q-card-section>
                 <q-card-section class="row items-center justify-between q-px-md q-pb-none">
                     <TimesheetNavigation
                         :is-disabled="timesheet_store.is_loading"
-                        :is-previous-limit="is_calendar_limit"
-                        @date-selected="value => onDateSelected(value)"
-                        @pressed-previous-button="timesheet_api.getPreviousPayPeriod()"
-                        @pressed-next-button="timesheet_api.getNextPayPeriod()"
+                        :is-previous-limit="timesheet_store.is_calendar_limit"
+                        @date-selected="onDateSelected"
+                        @pressed-previous-button="timesheet_api.getPreviousPeriodForUser(auth_store.user.email)"
+                        @pressed-next-button="timesheet_api.getNextPeriodForUser(auth_store.user.email)"
                     />
                 </q-card-section>
                 <!-- shift's colored legend -->
@@ -244,12 +127,12 @@ const on_request_delete = async ({ date, shift }: { date: string; shift: any })
                 />
                 <q-card-section horizontal>
                     <!-- display of shifts for 2 timesheets -->
-                    <TimesheetDetailsShifts
+                    <DetailedShiftList
                         :raw-data="timesheet_store.pay_period_employee_details"
                         :current-pay-period="timesheet_store.current_pay_period"
-                        @request-add="on_request_add"
-                        @request-edit="on_request_edit"
-                        @request-delete="on_request_delete"
+                        @request-add="onRequestAdd"
+                        @request-edit="onRequestEdit"
+                        @request-delete="onRequestDelete"
                     />                    
                     <q-inner-loading :showing="timesheet_store.is_loading" color="primary"/>
                 </q-card-section>
@@ -257,16 +140,17 @@ const on_request_delete = async ({ date, shift }: { date: string; shift: any })
         </div>
         <!-- read/edit/create/delete expense dialog -->
         <q-dialog
-            v-model="show_expenses_dialog"
+            v-model="expenses_store.is_dialog_open"
             persistent         
         >
             <q-card 
                 class="q-pa-md column"
                 style=" min-width: 70vw;"
             >
-                <q-inner-loading :showing="is_loading_expenses">
+                <q-inner-loading :showing="expenses_store.is_loading">
                     <q-spinner size="32px"/>
                 </q-inner-loading>
+
                 <!-- <q-banner 
                     v-if="expenses_error"
                     dense
@@ -276,29 +160,29 @@ const on_request_delete = async ({ date, shift }: { date: string; shift: any })
                 </q-banner> -->
 
                 <TimesheetDetailsExpenses
-                    v-if="expenses_data"
-                    :pay_period_no="expenses_data.pay_period_no"
-                    :pay_year="expenses_data.pay_year"
-                    :email="expenses_data.employee_email"
-                    :is_approved="expenses_data.is_approved"
-                    :initial_expenses="expenses_data.expenses"
-                    @save="on_save_expenses"
-                    @close="on_close_expenses"
-                    @error=" "
+                v-if="expenses_store.data"
+                :pay_period_no="expenses_store.data.pay_period_no"
+                :pay_year="expenses_store.data.pay_year"
+                :email="expenses_store.data.employee_email"
+                :is_approved="expenses_store.data.is_approved"
+                :initial_expenses="expenses_store.data.expenses"
+                @save="onSaveExpenses"
+                @close="onCloseExpenses"
+                @error=" "
                 />
             </q-card>
         </q-dialog>
 
         <!-- shift crud dialog -->
         <ShiftCrudDialog
-            v-model="is_dialog_open"
-            :mode="form_mode"
-            :date-iso="selected_date"
-            :email="auth_store.user.email"
-            :initial-shift="old_shift_ref || null"
-            :shift-options="shift_options"
-            @close="close_dialog"
-            @saved="onShiftSaved"
+        v-model="shift_store.is_open"
+        :mode="shift_store.mode"
+        :date-iso="shift_store.date_iso"
+        :email="auth_store.user.email"
+        :initial-shift="shift_store.initial_shift"
+        :shift-options="shift_options"
+        @close="shift_store.close"
+        @saved="onShiftSaved"
         />
     </q-page>
 </template>
\ No newline at end of file
diff --git a/src/modules/timesheets/services/timesheet-services.ts b/src/modules/timesheets/services/timesheet-services.ts
index caab15a..6a74466 100644
--- a/src/modules/timesheets/services/timesheet-services.ts
+++ b/src/modules/timesheets/services/timesheet-services.ts
@@ -1,10 +1,10 @@
 import { api } from "src/boot/axios";
-import type {Timesheet}  from "src/modules/timesheets/types/timesheet-interface";
-import type { CreateShiftPayload, CreateWeekShiftPayload } from "../types/timesheet-shifts-payload-interface";
 import type { PayPeriod } from "src/modules/shared/types/pay-period-interface";
 import type { PayPeriodEmployeeDetails } from "src/modules/timesheet-approval/types/timesheet-approval-pay-period-employee-details-interface";
 import type { PayPeriodOverview } from "src/modules/timesheet-approval/types/timesheet-approval-pay-period-overview-interface";
 import type { PayPeriodReportFilters } from "src/modules/timesheet-approval/types/timesheet-approval-pay-period-report-interface";
+import type { Timesheet } from "../types/timesheet.interfaces";
+import type { CreateShiftPayload, CreateWeekShiftPayload } from "../types/shift.interfaces";
 
 export const timesheetTempService = {
     //GET
diff --git a/src/modules/timesheets/timesheet-constants.ts b/src/modules/timesheets/timesheet-constants.ts
deleted file mode 100644
index 7ca8ae2..0000000
--- a/src/modules/timesheets/timesheet-constants.ts
+++ /dev/null
@@ -1 +0,0 @@
-//mock data
\ No newline at end of file
diff --git a/src/modules/timesheets/types/expense-validation.interface.ts b/src/modules/timesheets/types/expense-validation.interface.ts
new file mode 100644
index 0000000..64c3af0
--- /dev/null
+++ b/src/modules/timesheets/types/expense-validation.interface.ts
@@ -0,0 +1,34 @@
+export interface ApiErrorPayload {
+    status_code: number;
+    error_code?: string;
+    message?:    string;
+    context?:    Record<string, unknown>;
+}
+
+export class ExpensesValidationError extends Error {
+    status_code: number;
+    error_code?: string | undefined;
+    context?:    Record<string, unknown> | undefined;
+
+    constructor(payload: ApiErrorPayload) {
+        super(payload.message || 'Invalid expense payload');
+        this.name        = 'ExpensesValidationError';
+        this.status_code = payload.status_code;
+        this.error_code  = payload.error_code;
+        this.context     = payload.context;
+    }
+}
+
+export class ExpensesApiError extends Error {
+    status_code: number;
+    error_code?: string;
+    context?:    Record<string, unknown>;
+    constructor(payload: ApiErrorPayload) {
+        super(payload.message || 'Request failed');
+        this.name        = 'ExpensesApiError';
+        this.status_code = payload.status_code;
+
+        if(payload.error_code !== undefined) this.error_code = payload.error_code;
+        if(payload.context    !== undefined) this.context    = payload.context;
+    }
+}
\ No newline at end of file
diff --git a/src/modules/timesheets/types/expense.defaults.ts b/src/modules/timesheets/types/expense.defaults.ts
new file mode 100644
index 0000000..e69de29
diff --git a/src/modules/timesheets/types/expense.interfaces.ts b/src/modules/timesheets/types/expense.interfaces.ts
new file mode 100644
index 0000000..b4549f6
--- /dev/null
+++ b/src/modules/timesheets/types/expense.interfaces.ts
@@ -0,0 +1,47 @@
+import type { ExpenseType } from "./expense.types";
+
+export interface Expense {
+    is_approved:        boolean;
+    comment:            string;
+    amount:             number;
+    supervisor_comment: string;
+}
+
+export interface TimesheetExpense {
+    date:                string;
+    type:                string;
+    amount?:             number;
+    mileage?:            number;
+    comment?:            string;
+    supervisor_comment?: string;
+    is_approved?:        boolean;
+}
+
+export interface PayPeriodExpenses {
+    pay_period_no:  number;
+    pay_year:       number;
+    employee_email: string;
+    is_approved:    boolean;
+    expenses:       TimesheetExpense[];
+    totals: {
+        amount:              number;
+        mileage:             number;
+        reimbursable_total?: number;
+    }
+}
+
+export interface ExpensePayload{
+    date:     string;
+    type:     ExpenseType;
+    amount?:  number;
+    mileage?: number;
+    comment:  string;
+}
+
+export interface UpsertExpensesBody {
+    expenses: ExpensePayload[];
+}
+
+export interface UpsertExpensesResponse {
+    data: PayPeriodExpenses;
+}
\ No newline at end of file
diff --git a/src/modules/timesheets/types/expense.types.ts b/src/modules/timesheets/types/expense.types.ts
new file mode 100644
index 0000000..4d3b7eb
--- /dev/null
+++ b/src/modules/timesheets/types/expense.types.ts
@@ -0,0 +1,29 @@
+import type { TimesheetExpense } from "./expense.interfaces";
+
+export const EXPENSE_TYPE = [
+    'PER_DIEM',
+    'MILEAGE',
+    'EXPENSES',
+    'PRIME_GARDE',
+] as const;
+
+export type ExpenseType = (typeof EXPENSE_TYPE)[number];
+
+export const TYPES_WITH_MILEAGE_ONLY: Readonly<ExpenseType[]> = ['MILEAGE'];
+export const TYPES_WITH_AMOUNT_ONLY:  Readonly<ExpenseType[]> = [
+    'PER_DIEM',
+    'EXPENSES',
+    'PRIME_GARDE',
+];
+
+export type ExpenseTotals = { 
+    amount:  number;
+    mileage: number;
+};
+
+export type ExpenseSavePayload = {
+    pay_period_no: number;
+    pay_year:      number;
+    email:         string;
+    expenses:      TimesheetExpense[];
+};
\ No newline at end of file
diff --git a/src/modules/timesheets/types/shift.defaults.ts b/src/modules/timesheets/types/shift.defaults.ts
new file mode 100644
index 0000000..d95fbaa
--- /dev/null
+++ b/src/modules/timesheets/types/shift.defaults.ts
@@ -0,0 +1,11 @@
+import type { Shift } from "./shift.interfaces";
+
+export const default_shift: Readonly<Shift> = {
+    date: '',
+    start_time: '--:--',
+    end_time: '--:--',
+    type:'REGULAR',
+    comment: '',
+    is_approved: false,
+    is_remote: false,
+};
\ No newline at end of file
diff --git a/src/modules/timesheets/types/shift.interfaces.ts b/src/modules/timesheets/types/shift.interfaces.ts
new file mode 100644
index 0000000..055a4b4
--- /dev/null
+++ b/src/modules/timesheets/types/shift.interfaces.ts
@@ -0,0 +1,44 @@
+import type { ShiftKey, ShiftPayload, UpsertAction } from "./shift.types";
+
+export interface Shift {
+    date:        string;
+    type:        ShiftKey;
+    start_time:  string;
+    end_time:    string;
+    comment:     string;
+    is_approved: boolean;
+    is_remote:   boolean;
+}
+
+export interface CreateShiftPayload {
+    date:       string;
+    type:       ShiftKey;
+    start_time: string;
+    end_time:   string;
+    comment?:   string;
+    is_remote?: boolean;
+}
+
+export interface CreateWeekShiftPayload {
+    shifts: CreateShiftPayload[];
+}
+
+export interface UpsertShiftsBody {
+    old_shift?: ShiftPayload;
+    new_shift?: ShiftPayload;
+}
+
+export interface DayShift {
+    start_time: string;
+    end_time:   string;
+    type:       string;
+    is_remote:  boolean;
+    comment?:   string | null;
+}
+
+export interface UpsertShiftsResponse {
+    action: UpsertAction;
+    day:    DayShift[];
+}
+
+
diff --git a/src/modules/timesheets/types/shift.types.ts b/src/modules/timesheets/types/shift.types.ts
new file mode 100644
index 0000000..db42291
--- /dev/null
+++ b/src/modules/timesheets/types/shift.types.ts
@@ -0,0 +1,30 @@
+export const SHIFT_KEY = [
+    'REGULAR', 
+    'EVENING', 
+    'EMERGENCY', 
+    'HOLIDAY', 
+    'VACATION', 
+    'SICK'
+] as const;
+
+export type ShiftKey = typeof SHIFT_KEY[number];
+
+export type ShiftSelectOption = { value: ShiftKey; label: string };
+
+export type ShiftPayload = {
+    start_time: string;
+    end_time:   string;
+    type:       ShiftKey;
+    is_remote:  boolean;
+    comment?:   string;
+}
+
+export type ShiftLegendItem = {
+    type: 'REGULAR'|'EVENING'|'EMERGENCY'|'OVERTIME'|'VACATION'|'HOLIDAY'|'SICK';
+    color: string;
+    label_key: string;
+    text_color?: string;
+};
+
+export type UpsertAction = 'created' | 'updated' | 'deleted';
+
diff --git a/src/modules/timesheets/types/timesheet-details-interface.ts b/src/modules/timesheets/types/timesheet-details-interface.ts
deleted file mode 100644
index 400ef26..0000000
--- a/src/modules/timesheets/types/timesheet-details-interface.ts
+++ /dev/null
@@ -1,83 +0,0 @@
-import type { Shift } from "./timesheet-shift-interface";
-
-export interface TimesheetDetailsWeek {
-    is_approved: boolean;
-    shifts: WeekDay<TimesheetDetailsDailySchedule>;
-    expenses: WeekDay<TimesheetDetailsDailyExpenses>;
-}
-
-export interface TimesheetDetailsDailySchedule {
-    shifts: Shift[];
-    regular_hours: number;    
-    evening_hours: number;
-    emergency_hours: number;
-    overtime_hours: number;
-    total_hours: number;
-    comment: string;
-    short_date: string;     // ex. 08/24
-    break_duration?: number;
-}
-
-export interface Expense {
-    is_approved: boolean;
-    comment: string;
-    supervisor_comment: string;
-    amount: number;
-};
-
-type WeekDay<T> = {
-    sun: T;
-    mon: T;
-    tue: T;
-    wed: T;
-    thu: T;
-    fri: T;
-    sat: T;
-}
-
-
-interface TimesheetDetailsDailyExpenses {
-    cash: Expense[];
-    km: Expense[];
-    [otherType: string]: Expense[]; //for possible future types of expenses
-}
-
-//employee timesheet template
-export interface EmployeeTimesheetDetailsWeek {
-    is_approved: boolean;
-    shifts: WeekDay<TimesheetDetailsDailySchedule>;
-    expenses: WeekDay<TimesheetDetailsDailyExpenses>;
-}
-// empty default builder
-const makeWeek = <T>(factory: () => T): WeekDay<T> => ({
-    sun: factory(),
-    mon: factory(),
-    tue: factory(),
-    wed: factory(),
-    thu: factory(),
-    fri: factory(),
-    sat: factory(),
-});
-
-const emptyDailySchedule = (): TimesheetDetailsDailySchedule => ({
-    shifts: [],
-    regular_hours: 0,
-    evening_hours: 0,
-    emergency_hours: 0,
-    overtime_hours: 0,
-    total_hours: 0,
-    comment: "",
-    short_date: "",
-    break_duration: 0,
-});
-
-const emptyDailyExpenses = (): TimesheetDetailsDailyExpenses => ({
-    cash: [],
-    km: [],
-});
-
-export const default_timesheet_details_week = (): TimesheetDetailsWeek => ({
-    is_approved: false,
-    shifts: makeWeek(emptyDailySchedule),
-    expenses: makeWeek(emptyDailyExpenses),
-});
diff --git a/src/modules/timesheets/types/timesheet-expenses-interface.ts b/src/modules/timesheets/types/timesheet-expenses-interface.ts
deleted file mode 100644
index d7c67d2..0000000
--- a/src/modules/timesheets/types/timesheet-expenses-interface.ts
+++ /dev/null
@@ -1,21 +0,0 @@
-export interface TimesheetExpense {
-    date:                string;
-    amount?:             number;
-    mileage?:            number;
-    comment?:            string;
-    supervisor_comment?: string;
-    is_approved?:        boolean;
-    type:                string;
-}
-
-export const EXPENSE_TYPE = [
-    'PER_DIEM',
-    'MILEAGE',
-    'EXPENSES',
-    'PRIME_GARDE',
-] as const;
-
-export type ExpenseType = typeof EXPENSE_TYPE[number];
-
-export const TYPES_WITH_MILEAGE_ONLY: Readonly<ExpenseType[]> = ['MILEAGE'];
-export const TYPES_WITH_AMOUNT_ONLY:  Readonly<ExpenseType[]> = ['PER_DIEM', 'EXPENSES', 'PRIME_GARDE']
\ No newline at end of file
diff --git a/src/modules/timesheets/types/timesheet-expenses-list-interface.ts b/src/modules/timesheets/types/timesheet-expenses-list-interface.ts
deleted file mode 100644
index 5eb86b2..0000000
--- a/src/modules/timesheets/types/timesheet-expenses-list-interface.ts
+++ /dev/null
@@ -1,14 +0,0 @@
-import type { TimesheetExpense } from "./timesheet-expenses-interface";
-
-export interface PayPeriodExpenses {
-    pay_period_no:  number;
-    pay_year:       number;
-    employee_email: string;
-    is_approved:    boolean;
-    expenses:       TimesheetExpense[];
-    totals: {
-        amount:              number;
-        mileage:             number;
-        reimbursable_total?: number;
-    };
-}
\ No newline at end of file
diff --git a/src/modules/timesheets/types/timesheet-interface.ts b/src/modules/timesheets/types/timesheet-interface.ts
deleted file mode 100644
index 12334fd..0000000
--- a/src/modules/timesheets/types/timesheet-interface.ts
+++ /dev/null
@@ -1,28 +0,0 @@
-export interface Timesheet {
-    is_approved: boolean;
-    start_day: string;
-    end_day: string;
-    label: string;
-    shifts: Shifts[];
-    expenses: Expenses[];
-}
-
-type Shifts = {
-    bank_type: string;
-    date: string;
-    start_time: string;
-    end_time: string;
-    comment: string;
-    is_approved: boolean;
-    is_remote: boolean;
-}
-
-type Expenses = { 
-    bank_type: string;
-    date: string;
-    amount: number;
-    km: number;
-    comment: string;
-    supervisor_comment: string;
-    is_approved: boolean;
-}
\ No newline at end of file
diff --git a/src/modules/timesheets/types/timesheet-pay-period-details-overview-interface.ts b/src/modules/timesheets/types/timesheet-pay-period-details-overview-interface.ts
deleted file mode 100644
index 6c7a7f6..0000000
--- a/src/modules/timesheets/types/timesheet-pay-period-details-overview-interface.ts
+++ /dev/null
@@ -1,11 +0,0 @@
-import { default_timesheet_details_week, type TimesheetDetailsWeek } from "./timesheet-details-interface";
-
-export interface TimesheetPayPeriodDetailsOverview {
-    week1: TimesheetDetailsWeek;
-    week2: TimesheetDetailsWeek;
-};
-
-export const default_pay_period_employee_details = {
-    week1: default_timesheet_details_week(),
-    week2: default_timesheet_details_week(),
-}
\ No newline at end of file
diff --git a/src/modules/timesheets/types/timesheet-shift-interface.ts b/src/modules/timesheets/types/timesheet-shift-interface.ts
deleted file mode 100644
index 328e974..0000000
--- a/src/modules/timesheets/types/timesheet-shift-interface.ts
+++ /dev/null
@@ -1,19 +0,0 @@
-export interface Shift {
-    date       : string;
-    type       : string;
-    start_time : string;
-    end_time   : string;
-    comment    : string;
-    is_approved: boolean;
-    is_remote  : boolean;
-}
-
-export const default_shift: Shift = {
-    date: '',
-    start_time: '--:--',
-    end_time: '--:--',
-    type: '',
-    comment: '',
-    is_approved: false,
-    is_remote: false,
-}
diff --git a/src/modules/timesheets/types/timesheet-shifts-payload-interface.ts b/src/modules/timesheets/types/timesheet-shifts-payload-interface.ts
deleted file mode 100644
index dc8776d..0000000
--- a/src/modules/timesheets/types/timesheet-shifts-payload-interface.ts
+++ /dev/null
@@ -1,12 +0,0 @@
-export interface CreateShiftPayload  {
-    date: string;
-    type: string;
-    start_time: string;
-    end_time: string;
-    comment?: string;
-    is_remote?: boolean;
-};
-
-export interface CreateWeekShiftPayload  {
-    shifts: CreateShiftPayload[];
-}
\ No newline at end of file
diff --git a/src/modules/timesheets/types/timesheet.defaults.ts b/src/modules/timesheets/types/timesheet.defaults.ts
new file mode 100644
index 0000000..5e31768
--- /dev/null
+++ b/src/modules/timesheets/types/timesheet.defaults.ts
@@ -0,0 +1,39 @@
+import type { WeekDay } from "./timesheet.types";
+import type { 
+    TimesheetDetailsDailyExpenses, 
+    TimesheetDetailsDailySchedule, 
+    TimesheetDetailsWeek 
+} from "./timesheet.interfaces";
+
+const makeWeek = <T>(factory: ()=> T): WeekDay<T> => ({
+    sun: factory(),
+    mon: factory(),
+    tue: factory(),
+    wed: factory(),
+    thu: factory(),
+    fri: factory(),
+    sat: factory(),
+});
+
+const emptyDailySchedule = (): TimesheetDetailsDailySchedule => ({
+    shifts: [],
+    regular_hours: 0,
+    evening_hours: 0,
+    emergency_hours: 0,
+    overtime_hours: 0,
+    total_hours: 0,
+    comment: "",
+    short_date: "",
+    break_duration: 0,
+});
+
+const emptyDailyExpenses = (): TimesheetDetailsDailyExpenses => ({
+    cash: [],
+    km: [],
+});
+
+export const defaultTimesheetDetailsWeek = (): TimesheetDetailsWeek => ({
+    is_approved: false,
+    shifts: makeWeek(emptyDailySchedule),
+    expenses: makeWeek(emptyDailyExpenses),
+});
\ No newline at end of file
diff --git a/src/modules/timesheets/types/timesheet.interfaces.ts b/src/modules/timesheets/types/timesheet.interfaces.ts
new file mode 100644
index 0000000..034262d
--- /dev/null
+++ b/src/modules/timesheets/types/timesheet.interfaces.ts
@@ -0,0 +1,54 @@
+import type { Shift } from "./shift.interfaces";
+import type { 
+    TimesheetExpenseEntry, 
+    TimesheetShiftEntry, 
+    WeekDay 
+} from "./timesheet.types";
+
+
+export interface Timesheet {
+    is_approved: boolean;
+    start_day:   string;
+    end_day:     string;
+    label:       string;
+    shifts:      TimesheetShiftEntry[];
+    expenses:    TimesheetExpenseEntry[];
+}
+
+export interface TimesheetDetailsWeek {
+    is_approved: boolean;
+    shifts:   WeekDay<TimesheetDetailsDailySchedule>
+    expenses: WeekDay<TimesheetDetailsDailyExpenses>;
+}
+
+export interface TimesheetDetailsDailySchedule {
+    shifts:          Shift[];
+    regular_hours:   number;
+    evening_hours:   number;
+    emergency_hours: number;
+    overtime_hours:  number;
+    total_hours:     number;
+    comment:         string;
+    short_date:      string;
+    break_duration?: number;
+}
+
+export interface DailyExpense {
+    is_approved: boolean;
+    comment:     string;
+    amount:      number;
+    supervisor_comment: string;
+}
+
+export interface TimesheetDetailsDailyExpenses {
+    cash: DailyExpense[];
+    km:   DailyExpense[];
+    [otherType: string]: DailyExpense[];
+}
+
+
+export interface TimesheetPayPeriodDetailsOverview {
+    week1: TimesheetDetailsWeek;
+    week2: TimesheetDetailsWeek;
+}
+
diff --git a/src/modules/timesheets/types/timesheet.types.ts b/src/modules/timesheets/types/timesheet.types.ts
new file mode 100644
index 0000000..95144bd
--- /dev/null
+++ b/src/modules/timesheets/types/timesheet.types.ts
@@ -0,0 +1,29 @@
+export type TimesheetShiftEntry = {
+    bank_type:   string;
+    date:        string;
+    start_time:  string;
+    end_time:    string;
+    comment:     string;
+    is_approved: boolean;
+    is_remote:   boolean;
+};
+
+export type TimesheetExpenseEntry = {
+    bank_type:   string;
+    date:        string;
+    amount:      number;
+    km:          number;
+    comment:     string;
+    is_approved: boolean;
+    supervisor_comment: string;
+};
+
+export type WeekDay<T> = {
+    sun: T;
+    mon: T;
+    tue: T;
+    wed: T;
+    thu: T;
+    fri: T;
+    sat: T;
+};
\ No newline at end of file
diff --git a/src/modules/timesheets/types/ui.types.ts b/src/modules/timesheets/types/ui.types.ts
new file mode 100644
index 0000000..d738779
--- /dev/null
+++ b/src/modules/timesheets/types/ui.types.ts
@@ -0,0 +1,6 @@
+export type FormMode = 'create' | 'edit' | 'delete';
+
+export type PayPeriodLabel = {
+    start_date: string;
+    end_date:   string;
+};
\ No newline at end of file
diff --git a/src/modules/timesheets/utils/expense.util.ts b/src/modules/timesheets/utils/expense.util.ts
new file mode 100644
index 0000000..2ad7e3e
--- /dev/null
+++ b/src/modules/timesheets/utils/expense.util.ts
@@ -0,0 +1,76 @@
+import type { TimesheetExpense } from "../types/expense.interfaces";
+import type { ExpenseSavePayload, ExpenseTotals, ExpenseType } from "../types/expense.types";
+/* eslint-disable */
+//------------------ normalization / icons ------------------
+export const normExpenseType = (type: unknown): string => 
+    String(type ?? '').trim().toUpperCase();
+
+const icon_map: Record<string,string> = {
+    MILEAGE: 'time_to_leave',
+    EXPENSES: 'receipt_long',
+    PER_DIEM: 'hotel',
+    PRIME_GARDE: 'admin_panel_settings',
+};
+
+export const expenseTypeIcon = (type: unknown): string => {
+    const t = normExpenseType(type);
+    return (
+        icon_map[t.toLowerCase()] ??
+        icon_map[t.replace('-','_').toLowerCase()] ??
+        'help_outline'
+    );
+};
+
+//------------------ q-select options ------------------
+export const buildExpenseTypeOptions = ( types: readonly ExpenseType[], t: (key:string) => string):
+ { label: string; value: ExpenseType } [] =>
+    types.map((val)=> ({
+        label: t(`timesheet.expense.types.${val}`),
+        value: val,
+}));
+
+//------------------ totals ------------------
+export const computeExpenseTotals = (items: readonly TimesheetExpense[]): ExpenseTotals =>
+    items.reduce<ExpenseTotals>(
+        (acc, e) => ({
+            amount:  acc.amount  + (Number(e.amount)  || 0),
+            mileage: acc.mileage + (Number(e.mileage) || 0),
+        }),
+        { amount: 0, mileage: 0 }
+);
+
+//------------------ Quasar :rules=[] ------------------
+export const makeExpenseRules = (t: (key: string) => string, max_comment_char: number) => {
+    const isPresent = (val: unknown) => val !== undefined && val !== null && val !== '';
+
+    const typeRequired    = (val: unknown) => (!!val) || t('timesheet.expense.errors.type_required');
+
+    const amountRequired  = (val: unknown) => (isPresent(val)) || t('timesheet.expense.errors.amount_required_for_type');
+
+    const mileageRequired = (val: unknown) => (isPresent(val)) || t('timesheet.expense.erros.mileage_required_for_type');
+    
+    const commentRequired = (val: unknown) => (String(val ?? '').trim().length > 0) || t('timesheet.expense.errors.comment_required');
+
+    const commentTooLong  = (val: unknown) => (String(val ?? '').trim().length <= max_comment_char) || t('timesheet.expense.errors.comment_too_long');
+
+    return {
+        typeRequired,
+        amountRequired,
+        mileageRequired,
+        commentRequired,
+        commentTooLong,
+    };
+};
+
+//------------------ saving payload ------------------
+export const buildExpenseSavePayload = (args: {
+    pay_period_no:  number;
+    pay_year:       number;
+    email:          string;
+    expenses:       TimesheetExpense[];
+}): ExpenseSavePayload => ({
+    pay_period_no:  args.pay_period_no,
+    pay_year:       args.pay_year,
+    email:          args.email,
+    expenses:       args.expenses,
+});
\ No newline at end of file
diff --git a/src/modules/timesheets/utils/timesheet-expenses-validators.ts b/src/modules/timesheets/utils/expenses-validators.ts
similarity index 73%
rename from src/modules/timesheets/utils/timesheet-expenses-validators.ts
rename to src/modules/timesheets/utils/expenses-validators.ts
index b159800..392d776 100644
--- a/src/modules/timesheets/utils/timesheet-expenses-validators.ts
+++ b/src/modules/timesheets/utils/expenses-validators.ts
@@ -1,31 +1,11 @@
-import { type ExpenseType, type TimesheetExpense, TYPES_WITH_AMOUNT_ONLY, TYPES_WITH_MILEAGE_ONLY } from "../types/timesheet-expenses-interface";
-
-
-export const DATE_FORMAT_PATTERN = /^\d{4}-\d{2}-\d{2}$/;
-export const COMMENT_MAX_LENGTH = 512 as const;
-
-
-//errors handling
-export interface ApiErrorPayload {
-    status_code: number;
-    error_code?: string;
-    message?:    string;
-    context?:    Record<string, unknown>;
-}
-
-export class ExpensesValidationError extends Error {
-    status_code: number;
-    error_code?: string | undefined;
-    context?:    Record<string, unknown> | undefined;
-
-    constructor(payload: ApiErrorPayload) {
-        super(payload.message || 'Invalid expense payload');
-        this.name        = 'ExpensesValidationError';
-        this.status_code = payload.status_code;
-        this.error_code  = payload.error_code;
-        this.context     = payload.context;
-    }
-}
+import { COMMENT_MAX_LENGTH, DATE_FORMAT_PATTERN } from "../constants/expense.constants";
+import { ExpensesValidationError } from "../types/expense-validation.interface";
+import type { TimesheetExpense } from "../types/expense.interfaces";
+import { 
+    type ExpenseType, 
+    TYPES_WITH_AMOUNT_ONLY, 
+    TYPES_WITH_MILEAGE_ONLY 
+} from "../types/expense.types";
 
 //normalization helpers
 export const toNumOrUndefined = (value: unknown): number | undefined => {
@@ -34,21 +14,21 @@ export const toNumOrUndefined = (value: unknown): number | undefined => {
     return Number.isFinite(num) ? num : undefined;
 };
 
-export const normalize_comment = (input?: string): string | undefined => {
+export const normalizeComment = (input?: string): string | undefined => {
     if(typeof input === 'undefined' || input === null) return undefined;
     const trimmed = String(input).trim();
     return trimmed.length ? trimmed : undefined;
 };
 
-export const normalize_type = (input: string): string => (input ?? '').trim().toUpperCase();
+export const normalizeType = (input: string): string => (input ?? '').trim().toUpperCase();
 
-export const normalize_expense = (expense: TimesheetExpense): TimesheetExpense => {
-    const comment = normalize_comment(expense.comment);
+export const normalizeExpense = (expense: TimesheetExpense): TimesheetExpense => {
+    const comment = normalizeComment(expense.comment);
     const amount = toNumOrUndefined(expense.amount);
     const mileage = toNumOrUndefined(expense.mileage);
     return {
         date: (expense.date ?? '').trim(),
-        type: normalize_type(expense.type),
+        type: normalizeType(expense.type),
         ...(amount  !== undefined ? { amount }  : {}),
         ...(mileage !== undefined ? { mileage } : {}),
         ...(comment !== undefined ? { comment } : {}),
@@ -60,8 +40,8 @@ export const normalize_expense = (expense: TimesheetExpense): TimesheetExpense =
 };
 
 //UI validation error messages
-export const validate_expense_UI = (raw: TimesheetExpense, label: string = 'expense'): void => {
-    const expense = normalize_expense(raw);
+export const validateExpenseUI = (raw: TimesheetExpense, label: string = 'expense'): void => {
+    const expense = normalizeExpense(raw);
 
     //Date input validation
     if(!DATE_FORMAT_PATTERN.test(expense.date)) {
@@ -139,7 +119,7 @@ export const validate_expense_UI = (raw: TimesheetExpense, label: string = 'expe
 //totals per pay-period
 export const compute_expense_totals = (items: TimesheetExpense[]) => items.reduce(
     (acc, raw) => {
-        const expense = normalize_expense(raw);
+        const expense = normalizeExpense(raw);
         if(typeof expense.amount  === 'number' && expense.amount  > 0) acc.amount  +=  expense.amount;
         if(typeof expense.mileage === 'number' && expense.mileage > 0) acc.mileage += expense.mileage;
         return acc;
diff --git a/src/modules/timesheets/utils/shift.util.ts b/src/modules/timesheets/utils/shift.util.ts
new file mode 100644
index 0000000..11b86fe
--- /dev/null
+++ b/src/modules/timesheets/utils/shift.util.ts
@@ -0,0 +1,19 @@
+import type { ShiftKey, ShiftPayload, ShiftSelectOption } from "../types/shift.types";
+ /* eslint-disable */
+
+export const toShiftPayload = (shift: any): ShiftPayload => ({ 
+    start_time: String(shift.start_time),
+    end_time:   String(shift.end_time),
+    type:       String(shift.type).toUpperCase() as ShiftKey,
+    is_remote:  !!shift.is_remote,
+    ...(shift.comment ? { comment: String(shift.comment) } : {}), 
+});
+
+export const buildShiftOptions = (
+    keys: readonly string[],
+    t:(k: string) => string
+): ShiftSelectOption[] => 
+    keys.map((key) => ({
+        value: key as any,
+        label: t(`timesheet.shift.types.${key}`),
+    }));
\ No newline at end of file
diff --git a/src/modules/timesheets/utils/timesheet-format.util.ts b/src/modules/timesheets/utils/timesheet-format.util.ts
new file mode 100644
index 0000000..5c4775a
--- /dev/null
+++ b/src/modules/timesheets/utils/timesheet-format.util.ts
@@ -0,0 +1,17 @@
+import type { PayPeriodLabel } from "../types/ui.types";
+
+export const formatPayPeriodLabel = (
+    raw_label: string | undefined,
+    locale: string,
+    extractDate: (_input: string, _mask: string) => Date,
+    opts: Intl.DateTimeFormatOptions
+): PayPeriodLabel => {
+    const label = raw_label ?? '';
+    const dates = label.split('.');
+    if(dates.length < 2) return { start_date: '—', end_date:'—' };
+
+    const fmt   = new Intl.DateTimeFormat(locale, opts);
+    const start = fmt.format(extractDate(dates[0]!, 'YYYY-MM-DD'));
+    const end   = fmt.format(extractDate(dates[1]!, 'YYYY-MM-DD'));
+    return { start_date: start, end_date: end };
+}
\ No newline at end of file
diff --git a/src/stores/expense-store.ts b/src/stores/expense-store.ts
new file mode 100644
index 0000000..b66aedf
--- /dev/null
+++ b/src/stores/expense-store.ts
@@ -0,0 +1,88 @@
+import { ref } from "vue";
+import { defineStore } from "pinia";
+import { type PayPeriodExpenses } from "src/modules/timesheets/types/expense.interfaces";
+import { ExpensesApiError }  from "src/modules/timesheets/types/expense-validation.interface";
+import { getPayPeriodExpenses, putPayPeriodExpenses } from "src/modules/timesheets/composables/api/use-expense-api";
+
+/* eslint-disable */
+export const useExpensesStore = defineStore('expenses', () => {
+    const is_dialog_open = ref(false);
+    const is_loading     = ref(false);
+    const data           = ref<PayPeriodExpenses | null>(null);
+    const error          = ref<string | null>(null);
+
+    const setErrorFrom = (err: unknown, t?: (_key: string) => string) => {
+        const e = err as any;
+        error.value = (err instanceof ExpensesApiError && t 
+                        ? t(e.message): undefined)
+                        || e?.message
+                        || 'Unknown error';
+    };
+
+    const openDialog = async (
+        params: { email: string; pay_year: number; pay_period_no: number; t?: (_key: string)=> string}) => {
+            is_dialog_open.value = true;
+            is_loading.value     = true;
+            error.value          = null;
+            try {
+                const response = await getPayPeriodExpenses(
+                    params.email,
+                    params.pay_year,
+                    params.pay_period_no,
+                );
+                data.value = response;
+            } catch (err) {
+                setErrorFrom(err, params.t);
+                data.value = {
+                    pay_period_no:  params.pay_period_no,
+                    pay_year:       params.pay_year,
+                    employee_email:  params.email,
+                    is_approved:    false,
+                    expenses:       [],
+                    totals:         { amount: 0, mileage: 0},
+                };
+            } finally {
+                is_loading.value = false;
+            }
+    }
+
+    const saveExpenses = async (payload: {
+        email: string;
+        pay_year: number;
+        pay_period_no: number;
+        expenses: any[]; t?: (_key: string) => string
+    }) => {
+        is_loading.value = true;
+        error.value      = null;
+
+        try {
+            const updated = await putPayPeriodExpenses(
+                payload.email,
+                payload.pay_year,
+                payload.pay_period_no,
+                payload.expenses
+            );
+            data.value = updated;
+            is_dialog_open.value = false;
+        } catch (err) {
+            setErrorFrom(err, payload.t);
+        } finally {
+            is_loading.value = false;
+        }
+    };
+
+    const closeDialog = () => {
+        error.value          = null;
+        is_dialog_open.value = false;
+    };
+
+    return {
+        is_dialog_open,
+        is_loading,
+        data,
+        error,
+        openDialog,
+        saveExpenses,
+        closeDialog,
+    };
+});
\ No newline at end of file
diff --git a/src/stores/shift-store.ts b/src/stores/shift-store.ts
new file mode 100644
index 0000000..5acf6b2
--- /dev/null
+++ b/src/stores/shift-store.ts
@@ -0,0 +1,50 @@
+import { defineStore } from "pinia";
+import { ref } from "vue";
+import { toShiftPayload } from "src/modules/timesheets/utils/shift.util";
+import type { FormMode } from "src/modules/timesheets/types/ui.types";
+import type { ShiftPayload } from "src/modules/timesheets/types/shift.types";
+
+ /* eslint-disable */
+export const useShiftStore = defineStore('shift', () => {
+    const is_open       = ref(false);
+    const mode          = ref<FormMode>('create');
+    const date_iso      = ref<string>('');
+    const initial_shift = ref<ShiftPayload | null>(null);
+
+    const open = (nextMode: FormMode, date: string, payload: ShiftPayload | null) => {
+        mode.value          = nextMode;
+        date_iso.value      = date;
+        initial_shift.value = payload;
+        is_open.value       = true;
+    };
+
+    const openCreate = (date: string) => {
+        open('create', date, null);
+    };
+
+    const openEdit = (date: string, shift: any) => {
+        open('edit', date, toShiftPayload(shift as any));
+    };
+
+    const openDelete = (date: string, shift: any) => {
+        open('delete', date, toShiftPayload(shift as any));
+    }
+
+    const close = () => { 
+        is_open.value       = false;
+        mode.value          = 'create';
+        date_iso.value      = '';
+        initial_shift.value = null;
+    };
+
+    return {
+        is_open,
+        mode,
+        date_iso,
+        initial_shift,
+        openCreate,
+        openEdit,
+        openDelete,
+        close,
+    };
+})
\ No newline at end of file
diff --git a/src/stores/timesheet-store.ts b/src/stores/timesheet-store.ts
index 936ee33..472f9d9 100644
--- a/src/stores/timesheet-store.ts
+++ b/src/stores/timesheet-store.ts
@@ -1,13 +1,14 @@
+import { date } from 'quasar';
 import { defineStore } from 'pinia';
-import { ref } from 'vue';
+import { computed, ref } from 'vue';
 import { timesheetApprovalService } from 'src/modules/timesheet-approval/services/services-timesheet-approval';
 import { timesheetTempService } from 'src/modules/timesheets/services/timesheet-services';
 import { default_pay_period_employee_details, type PayPeriodEmployeeDetails } from 'src/modules/timesheet-approval/types/timesheet-approval-pay-period-employee-details-interface';
 import type { PayPeriod } from 'src/modules/shared/types/pay-period-interface';
 import type { PayPeriodOverviewEmployee } from "src/modules/timesheet-approval/types/timesheet-approval-pay-period-overview-employee-interface";
 import type { PayPeriodReportFilters } from 'src/modules/timesheet-approval/types/timesheet-approval-pay-period-report-interface';
-import type { Timesheet } from 'src/modules/timesheets/types/timesheet-interface';
-import type { CreateShiftPayload } from 'src/modules/timesheets/types/timesheet-shifts-payload-interface';
+import type { Timesheet } from 'src/modules/timesheets/types/timesheet.interfaces';
+import type { CreateShiftPayload } from 'src/modules/timesheets/types/shift.interfaces';
 
 const default_pay_period: PayPeriod = { 
     pay_period_no: -1,
@@ -127,6 +128,33 @@ export const useTimesheetStore = defineStore('timesheet', () => {
         }
     };
 
+    //employee timesheet
+    const loadByIsoDate = async (iso_date: string, employee_email: string) => {
+        const ok = await getPayPeriodByDate(iso_date);
+        if(ok) {
+            await getTimesheetsByPayPeriodAndEmail(employee_email);
+        }
+        return ok;
+    };
+
+    //employee timesheet
+    const is_calendar_limit = computed(()=> 
+        current_pay_period.value.pay_year === 2024 &&
+        current_pay_period.value.pay_period_no <= 1
+    );
+
+    //employee timesheet
+    const refreshCurrentPeriodForUser = async (employee_email: string) => {
+        await getTimesheetsByPayPeriodAndEmail(employee_email);
+    };
+
+    //employee timesheet
+    const loadToday = async (employee_email: string) => {
+        const today = date.formatDate(new Date(), 'YYYY-MM-DD');
+        return loadByIsoDate(today, employee_email);
+    }
+
+
     const getTimesheetsByPayPeriodAndEmail = async (employee_email: string) => {
         is_loading.value = true;
 
@@ -170,6 +198,10 @@ export const useTimesheetStore = defineStore('timesheet', () => {
         pay_period_employee_details,
         current_timesheet,
         is_loading,
+        is_calendar_limit,
+        loadByIsoDate,
+        refreshCurrentPeriodForUser,
+        loadToday,
         getPayPeriodByDate,
         getTimesheetByEmail,
         createTimesheetShifts,
diff --git a/src/utils/with-loading.util.ts b/src/utils/with-loading.util.ts
new file mode 100644
index 0000000..2f323a5
--- /dev/null
+++ b/src/utils/with-loading.util.ts
@@ -0,0 +1,10 @@
+import type { Ref } from "vue";
+
+export const withLoading = async <T>(loading_ref: Ref<boolean>, fn: ()=> Promise<T>): Promise<T> => {
+    loading_ref.value = true;
+    try{
+        return await fn();
+    } finally {
+        loading_ref.value = false;
+    }
+};
\ No newline at end of file