diff --git a/BACKEND/Modules/Admin/app/Http/Controllers/CategoryController.php b/BACKEND/Modules/Admin/app/Http/Controllers/CategoryController.php
index 0150d30..408787a 100644
--- a/BACKEND/Modules/Admin/app/Http/Controllers/CategoryController.php
+++ b/BACKEND/Modules/Admin/app/Http/Controllers/CategoryController.php
@@ -3,6 +3,7 @@
 namespace Modules\Admin\app\Http\Controllers;
 
 use App\Http\Controllers\Controller;
+use Carbon\Carbon;
 use Illuminate\Http\Request;
 use Modules\Admin\app\Models\Category;
 
@@ -29,4 +30,45 @@ class CategoryController extends Controller
         $data = Category::where('c_type', '=', $type)->where('c_active', '=', 1)->select('id', 'c_code', 'c_name', 'c_value', 'c_type')->get();
         return $data;
     }
+
+    public function workDays()
+    {
+        $saturday_work_schedules = Category::where('c_type', 'SATURDAY_WORK_SCHEDULE')
+            ->get();
+
+        return response()->json([
+            'data' => $saturday_work_schedules,
+            'status' => true
+        ]);
+    }
+
+    public function updateWorkDays(Request $request)
+    {
+        $request->validate([
+            'c_code' => 'required|date_format:d-m-Y',
+        ]);
+
+        $schedule = Category::where('c_type', 'SATURDAY_WORK_SCHEDULE')->first();
+
+        if (!$schedule) {
+            $schedule = Category::create([
+                'c_type' => 'SATURDAY_WORK_SCHEDULE',
+                'c_name' => "Ngày bắt đầu làm việc thứ 7 trong năm",
+                'c_code' => $request->c_code,
+                'c_value' => Carbon::now()->year,
+                'c_active' => true,
+                'created_at' => now(),
+                'updated_at' => now(),
+            ]);
+        } else {
+            $schedule->update([
+                'c_code' => $request->c_code,
+            ]);
+        }
+
+        return response()->json([
+            'status' => true,
+            'message' => 'Saturday work schedule updated successfully'
+        ]);
+    }
 }
diff --git a/BACKEND/Modules/Admin/app/Models/Category.php b/BACKEND/Modules/Admin/app/Models/Category.php
index 11a4424..356d346 100644
--- a/BACKEND/Modules/Admin/app/Models/Category.php
+++ b/BACKEND/Modules/Admin/app/Models/Category.php
@@ -8,4 +8,12 @@ use Illuminate\Database\Eloquent\Model;
 class Category extends Model
 {
     use HasFactory;
+
+    protected $fillable = [
+        'c_type',
+        'c_name',
+        'c_code',
+        'c_value',
+        'c_active',
+    ];
 }
diff --git a/BACKEND/Modules/Admin/routes/api.php b/BACKEND/Modules/Admin/routes/api.php
index c555911..dc662b2 100755
--- a/BACKEND/Modules/Admin/routes/api.php
+++ b/BACKEND/Modules/Admin/routes/api.php
@@ -149,6 +149,8 @@ Route::middleware('api')
                 'prefix' => 'category',
             ], function () {
                 Route::get('/get-list-master', [CategoryController::class, 'getListMaster']);
+                Route::get('/work-days', [CategoryController::class, 'workDays']);
+                Route::put('/update-work-days', [CategoryController::class, 'updateWorkDays']);
             });
 
             Route::group([
diff --git a/FRONTEND/src/api/Admin.ts b/FRONTEND/src/api/Admin.ts
index 1de63ba..822388b 100755
--- a/FRONTEND/src/api/Admin.ts
+++ b/FRONTEND/src/api/Admin.ts
@@ -35,6 +35,8 @@ export const updateWorkingDays =
 
 //Category
 export const getListMaster = API_URL + 'v1/admin/category/get-list-master'
+export const getWorkDay = API_URL + 'v1/admin/category/work-days'
+export const updateWorkDay = API_URL + 'v1/admin/category/update-work-days'
 
 //LeaveManagement
 export const getLeaveManagement = API_URL + 'v1/admin/leave-management'
diff --git a/FRONTEND/src/pages/OrganizationSettings/OrganizationSettings.tsx b/FRONTEND/src/pages/OrganizationSettings/OrganizationSettings.tsx
index 718f301..fae84e4 100644
--- a/FRONTEND/src/pages/OrganizationSettings/OrganizationSettings.tsx
+++ b/FRONTEND/src/pages/OrganizationSettings/OrganizationSettings.tsx
@@ -1,28 +1,46 @@
 import { useEffect, useState } from 'react'
 import {
+  Alert,
   Box,
   Button,
+  Code,
   Dialog,
   Flex,
+  Grid,
   Group,
   Loader,
+  LoadingOverlay,
   Modal,
+  Paper,
   Select,
   Tabs,
   Text,
   TextInput,
+  Title,
 } from '@mantine/core'
 import classes from './OrganizationSettings.module.css'
 import DataTableAll from '@/components/DataTable/DataTable'
-import { get, post } from '@/rtk/helpers/apiService'
+import { get, post, put } from '@/rtk/helpers/apiService'
 import { notifications } from '@mantine/notifications'
-import { createTechnical, deleteTechnical, listTechnical } from '@/api/Admin'
+import {
+  createTechnical,
+  deleteTechnical,
+  getWorkDay,
+  listTechnical,
+  updateWorkDay,
+} from '@/api/Admin'
 import { useForm } from '@mantine/form'
 import { Xdelete } from '@/rtk/helpers/CRUD'
 import moment from 'moment'
+import { DatePickerInput } from '@mantine/dates'
+import { IconInfoCircle } from '@tabler/icons-react'
+import dayjs from 'dayjs'
+import customParseFormat from 'dayjs/plugin/customParseFormat'
+
+dayjs.extend(customParseFormat)
 
 function OrganizationSettings() {
-  const [activeTab, setActiveTab] = useState<string | null>('technical')
+  const [activeTab, setActiveTab] = useState<string | null>('work-day')
 
   return (
     <div>
@@ -36,17 +54,17 @@ function OrganizationSettings() {
       <Box w="100%" display={'flex'} mt={15} ml={10}>
         <Tabs w="100%" value={activeTab} onChange={setActiveTab}>
           <Tabs.List>
+            <Tabs.Tab value="work-day">Work Day Setting</Tabs.Tab>
             <Tabs.Tab value="technical">Technical Setting</Tabs.Tab>
-            <Tabs.Tab value="second">Setting 2</Tabs.Tab>
             <Tabs.Tab value="third">Setting 3</Tabs.Tab>
           </Tabs.List>
 
-          <Tabs.Panel value="technical" pt="xs">
-            <TechnicalSettingTab />
+          <Tabs.Panel value="work-day" pt="xs">
+            <WorkDaySettingTab />
           </Tabs.Panel>
 
-          <Tabs.Panel value="second" pt="xs">
-            Setting 2
+          <Tabs.Panel value="technical" pt="xs">
+            <TechnicalSettingTab />
           </Tabs.Panel>
 
           <Tabs.Panel value="third" pt="xs">
@@ -100,8 +118,8 @@ const TechnicalSettingTab = () => {
                 ? row?.level === 1
                   ? { backgroundColor: '#d9d2e9' }
                   : row?.level === 2
-                  ? { backgroundColor: '#ffd966' }
-                  : { backgroundColor: '#cfe2f3' }
+                    ? { backgroundColor: '#ffd966' }
+                    : { backgroundColor: '#cfe2f3' }
                 : { backgroundColor: '' }
             }
             fw={500}
@@ -330,4 +348,126 @@ const TechnicalSettingTab = () => {
   )
 }
 
+const WorkDaySettingTab = () => {
+  const [workDay, setWorkDay] = useState<any>(null)
+  const [isLoading, setIsLoading] = useState(false)
+  const [isSaving, setIsSaving] = useState(false)
+  const [selectedDate, setSelectedDate] = useState<Date | null>(null)
+
+  useEffect(() => {
+    getWorkDays()
+  }, [])
+
+  const getWorkDays = async () => {
+    try {
+      setIsLoading(true)
+      const res = await get(getWorkDay, {})
+      if (res.status && res.data?.length > 0) {
+        const item = res.data[0]
+        setWorkDay(item)
+        const parsed = dayjs(item.c_code, 'DD-MM-YYYY').toDate()
+        setSelectedDate(parsed)
+      }
+    } catch (error: any) {
+      notifications.show({
+        title: 'Error',
+        message: error.message ?? error,
+        color: 'red',
+      })
+    } finally {
+      setIsLoading(false)
+    }
+  }
+
+  const handleSave = async () => {
+    if (!selectedDate) return
+    try {
+      setIsSaving(true)
+      const payload = {
+        c_code: dayjs(selectedDate).format('DD-MM-YYYY'),
+      }
+      const res = await put(`${updateWorkDay}`, payload)
+      if (res.status) {
+        notifications.show({
+          title: 'Success',
+          message: res.message,
+          color: 'green',
+        })
+      }
+    } catch (error: any) {
+      notifications.show({
+        title: 'Error',
+        message: error.message ?? error,
+        color: 'red',
+      })
+    } finally {
+      setIsSaving(false)
+    }
+  }
+
+  const handleReset = () => {
+    if (!workDay) return
+    const parsed = dayjs(workDay.c_code, 'DD-MM-YYYY').toDate()
+    setSelectedDate(parsed)
+  }
+
+  return (
+    <Box>
+      <LoadingOverlay visible={isLoading} />
+
+      <Title order={4} mb="xs">
+        Set up Saturday as a working day.
+      </Title>
+
+      <Paper withBorder p="lg" radius="md">
+        <Grid>
+          <Grid.Col span={12}>
+            <DatePickerInput
+              label="Saturday Work Start Date"
+              description="Weeks starting from this date will include Saturday as a working day."
+              placeholder="Select Date"
+              value={selectedDate}
+              onChange={setSelectedDate}
+              valueFormat="DD/MM/YYYY"
+              clearable={false}
+              excludeDate={(date) => date.getDay() === 0}
+            />
+          </Grid.Col>
+        </Grid>
+
+        {selectedDate && (
+          <Alert
+            mt="md"
+            variant="light"
+            color="blue"
+            icon={<IconInfoCircle size={16} />}
+          >
+            Starting from{' '}
+            <Text span fw={500}>
+              {dayjs(selectedDate).format('DD/MM/YYYY')}
+            </Text>
+            , Saturdays will be treated as working days in applicable weeks.
+          </Alert>
+        )}
+
+        <Group justify="flex-end" mt="lg" gap="sm">
+          <Button variant="default" onClick={handleReset} disabled={isSaving}>
+            Cancel
+          </Button>
+          <Button onClick={handleSave} loading={isSaving}>
+            Save change
+          </Button>
+        </Group>
+      </Paper>
+
+      <Paper withBorder p="sm" radius="md" mt="sm" bg="gray.0">
+        <Text size="xs" c="dimmed">
+          Setting type:{' '}
+          <Code>{workDay?.c_type ?? 'SATURDAY_WORK_SCHEDULE'}</Code>
+        </Text>
+      </Paper>
+    </Box>
+  )
+}
+
 export default OrganizationSettings