diff --git a/frontend/src/views/admin/DashboardView.vue b/frontend/src/views/admin/DashboardView.vue
index 8b7ff632..bc8b5aa2 100644
--- a/frontend/src/views/admin/DashboardView.vue
+++ b/frontend/src/views/admin/DashboardView.vue
@@ -348,12 +348,20 @@ const formatLocalDate = (date: Date): string => {
   return `${date.getFullYear()}-${String(date.getMonth() + 1).padStart(2, '0')}-${String(date.getDate()).padStart(2, '0')}`
 }
 
-const getTodayLocalDate = () => formatLocalDate(new Date())
+const getLast24HoursRangeDates = (): { start: string; end: string } => {
+  const end = new Date()
+  const start = new Date(end.getTime() - 24 * 60 * 60 * 1000)
+  return {
+    start: formatLocalDate(start),
+    end: formatLocalDate(end)
+  }
+}
 
 // Date range
 const granularity = ref<'day' | 'hour'>('hour')
-const startDate = ref(getTodayLocalDate())
-const endDate = ref(getTodayLocalDate())
+const defaultRange = getLast24HoursRangeDates()
+const startDate = ref(defaultRange.start)
+const endDate = ref(defaultRange.end)
 
 // Granularity options for Select component
 const granularityOptions = computed(() => [
diff --git a/frontend/src/views/admin/__tests__/DashboardView.spec.ts b/frontend/src/views/admin/__tests__/DashboardView.spec.ts
new file mode 100644
index 00000000..7cb51232
--- /dev/null
+++ b/frontend/src/views/admin/__tests__/DashboardView.spec.ts
@@ -0,0 +1,143 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { flushPromises, mount } from '@vue/test-utils'
+
+import type { DashboardStats } from '@/types'
+import DashboardView from '../DashboardView.vue'
+
+const { getSnapshotV2, getUserUsageTrend, getUserSpendingRanking } = vi.hoisted(() => ({
+  getSnapshotV2: vi.fn(),
+  getUserUsageTrend: vi.fn(),
+  getUserSpendingRanking: vi.fn()
+}))
+
+vi.mock('@/api/admin', () => ({
+  adminAPI: {
+    dashboard: {
+      getSnapshotV2,
+      getUserUsageTrend,
+      getUserSpendingRanking
+    }
+  }
+}))
+
+vi.mock('@/stores/app', () => ({
+  useAppStore: () => ({
+    showError: vi.fn()
+  })
+}))
+
+vi.mock('vue-router', () => ({
+  useRouter: () => ({
+    push: vi.fn()
+  })
+}))
+
+vi.mock('vue-i18n', async () => {
+  const actual = await vi.importActual<typeof import('vue-i18n')>('vue-i18n')
+  return {
+    ...actual,
+    useI18n: () => ({
+      t: (key: string) => key
+    })
+  }
+})
+
+const formatLocalDate = (date: Date): string => {
+  const year = date.getFullYear()
+  const month = String(date.getMonth() + 1).padStart(2, '0')
+  const day = String(date.getDate()).padStart(2, '0')
+  return `${year}-${month}-${day}`
+}
+
+const createDashboardStats = (): DashboardStats => ({
+  total_users: 0,
+  today_new_users: 0,
+  active_users: 0,
+  hourly_active_users: 0,
+  stats_updated_at: '',
+  stats_stale: false,
+  total_api_keys: 0,
+  active_api_keys: 0,
+  total_accounts: 0,
+  normal_accounts: 0,
+  error_accounts: 0,
+  ratelimit_accounts: 0,
+  overload_accounts: 0,
+  total_requests: 0,
+  total_input_tokens: 0,
+  total_output_tokens: 0,
+  total_cache_creation_tokens: 0,
+  total_cache_read_tokens: 0,
+  total_tokens: 0,
+  total_cost: 0,
+  total_actual_cost: 0,
+  today_requests: 0,
+  today_input_tokens: 0,
+  today_output_tokens: 0,
+  today_cache_creation_tokens: 0,
+  today_cache_read_tokens: 0,
+  today_tokens: 0,
+  today_cost: 0,
+  today_actual_cost: 0,
+  average_duration_ms: 0,
+  uptime: 0,
+  rpm: 0,
+  tpm: 0
+})
+
+describe('admin DashboardView', () => {
+  beforeEach(() => {
+    getSnapshotV2.mockReset()
+    getUserUsageTrend.mockReset()
+    getUserSpendingRanking.mockReset()
+
+    getSnapshotV2.mockResolvedValue({
+      stats: createDashboardStats(),
+      trend: [],
+      models: []
+    })
+    getUserUsageTrend.mockResolvedValue({
+      trend: [],
+      start_date: '',
+      end_date: '',
+      granularity: 'hour'
+    })
+    getUserSpendingRanking.mockResolvedValue({
+      ranking: [],
+      total_actual_cost: 0,
+      total_requests: 0,
+      total_tokens: 0,
+      start_date: '',
+      end_date: ''
+    })
+  })
+
+  it('uses last 24 hours as default dashboard range', async () => {
+    mount(DashboardView, {
+      global: {
+        stubs: {
+          AppLayout: { template: '<div><slot /></div>' },
+          LoadingSpinner: true,
+          Icon: true,
+          DateRangePicker: true,
+          Select: true,
+          ModelDistributionChart: true,
+          TokenUsageTrend: true,
+          Line: true
+        }
+      }
+    })
+
+    await flushPromises()
+
+    const now = new Date()
+    const yesterday = new Date(now.getTime() - 24 * 60 * 60 * 1000)
+
+    expect(getSnapshotV2).toHaveBeenCalledTimes(1)
+    expect(getSnapshotV2).toHaveBeenCalledWith(expect.objectContaining({
+      start_date: formatLocalDate(yesterday),
+      end_date: formatLocalDate(now),
+      granularity: 'hour'
+    }))
+  })
+})