diff --git a/frontend/src/lib/components/admin/DiscountsManagement.svelte b/frontend/src/lib/components/admin/DiscountsManagement.svelte
index bf9b4e5..35fc927 100644
--- a/frontend/src/lib/components/admin/DiscountsManagement.svelte
+++ b/frontend/src/lib/components/admin/DiscountsManagement.svelte
@@ -1,4 +1,5 @@
 <script lang="ts">
+	import { SvelteDate } from 'svelte/reactivity';
 	import { authStore } from '$lib/stores/auth.svelte';
 	import { toast } from 'svelte-sonner';
 	import { Button } from '$lib/components/ui/button';
@@ -95,7 +96,7 @@
 		if (form.discount_percent <= 0 || form.discount_percent > 100) return false;
 		if (form.campaign_type === 'time_based') {
 			if (!form.start_date || !form.end_date) return false;
-			if (new Date(form.end_date) <= new Date(form.start_date)) return false;
+			if (new SvelteDate(form.end_date) <= new SvelteDate(form.start_date)) return false;
 		}
 		if (form.campaign_type === 'milestone') {
 			if (form.milestone_value <= 0) return false;
diff --git a/frontend/src/lib/components/admin/HolidayHours.svelte b/frontend/src/lib/components/admin/HolidayHours.svelte
index 4165484..706d3bb 100644
--- a/frontend/src/lib/components/admin/HolidayHours.svelte
+++ b/frontend/src/lib/components/admin/HolidayHours.svelte
@@ -535,7 +535,7 @@
 										class="w-24 text-sm"
 									>
 										{#each Array(24) as _, hour}
-											{#each TIME15 as min}
+											{#each TIME15 as min (min)}
 												<option value="{String(hour).padStart(2,'0')}:{min}">{String(hour).padStart(2,'0')}:{min}</option>
 											{/each}
 										{/each}
@@ -548,7 +548,7 @@
 										class="w-24 text-sm"
 									>
 										{#each Array(24) as _, hour}
-											{#each TIME15 as min}
+											{#each TIME15 as min (min)}
 												<option value="{String(hour).padStart(2,'0')}:{min}">{String(hour).padStart(2,'0')}:{min}</option>
 											{/each}
 										{/each}
diff --git a/frontend/src/lib/components/admin/TimeBlockers.svelte b/frontend/src/lib/components/admin/TimeBlockers.svelte
index aa941d4..9eff85c 100644
--- a/frontend/src/lib/components/admin/TimeBlockers.svelte
+++ b/frontend/src/lib/components/admin/TimeBlockers.svelte
@@ -2,6 +2,7 @@
 	import { authStore } from '$lib/stores/auth.svelte';
 	import { SvelteDate } from 'svelte/reactivity';
 	import { toast } from 'svelte-sonner';
+	import { formatDuration } from '$lib/utils/format';
 
 	import { Button } from '$lib/components/ui/button';
 	import * as Card from '$lib/components/ui/card';
@@ -110,7 +111,7 @@
 
 	function getWorkingHoursForDate(dateStr: string): WorkingHourRow | null {
 		if (!dateStr || defaultHours.length === 0) return null;
-		const d = new Date(dateStr + 'T00:00:00');
+		const d = new SvelteDate(dateStr + 'T00:00:00');
 		const jsDay = d.getDay();
 		const weekday = jsDay === 0 ? 6 : jsDay - 1;
 		return defaultHours.find((h) => h.weekday === weekday) ?? null;
@@ -152,16 +153,11 @@
 		return options;
 	});
 
-	function formatDuration(minutes: number): string {
-		if (minutes < 60) return `${minutes}m`;
-		const h = Math.floor(minutes / 60);
-		const m = minutes % 60;
-		return m > 0 ? `${h}h ${m}m` : `${h}h`;
-	}
+
 
 	function formatRelativeTime(iso: string): string {
-		const d = new Date(iso);
-		const now = new Date();
+		const d = new SvelteDate(iso);
+		const now = new SvelteDate();
 		const diffMs = d.getTime() - now.getTime();
 		if (diffMs < 0) {
 			const absMin = Math.floor(Math.abs(diffMs) / 60000);
@@ -178,7 +174,7 @@
 	}
 
 	let sortedBlockers = $derived.by(() => {
-		return [...blockers].sort((a, b) => new Date(a.start_time).getTime() - new Date(b.start_time).getTime());
+		return [...blockers].sort((a, b) => new SvelteDate(a.start_time).getTime() - new SvelteDate(b.start_time).getTime());
 	});
 
 	let totalPages = $derived.by(() => Math.max(1, Math.ceil(sortedBlockers.length / PAGE_SIZE)));
@@ -261,8 +257,8 @@
 			return;
 		}
 
-		const blockerStart = new Date(startIso);
-		const blockerEnd = new Date(endIso);
+		const blockerStart = new SvelteDate(startIso);
+		const blockerEnd = new SvelteDate(endIso);
 		if (blockerEnd.getTime() <= blockerStart.getTime()) {
 			overlappingBookings = [];
 			hasOverlap = false;
@@ -288,8 +284,8 @@
 				const allBookings: OverlappingBooking[] = data.bookings || [];
 				// Client-side filter: only bookings that overlap with the proposed blocker timespan
 				const filtered = allBookings.filter((b) => {
-					const bStart = new Date(b.start_time);
-					const bEnd = new Date(bStart.getTime() + b.duration_minutes * 60000);
+					const bStart = new SvelteDate(b.start_time);
+					const bEnd = new SvelteDate(bStart.getTime() + b.duration_minutes * 60000);
 					return bStart < blockerEnd && bEnd > blockerStart;
 				});
 				overlappingBookings = filtered;
@@ -701,7 +697,7 @@
 									onStartTimeChange();
 								}}
 							>
-								{#each availableStartOptions as opt}
+								{#each availableStartOptions as opt (opt.totalMin)}
 									<option value={`${opt.hour}:${opt.minute}:${opt.period}`}>
 										{opt.label}
 									</option>
@@ -736,7 +732,7 @@
 							onEndTimeChange();
 						}}
 					>
-						{#each availableEndOptions as opt}
+						{#each availableEndOptions as opt (opt.totalMin)}
 							<option value={`${opt.hour}:${opt.minute}:${opt.period}`}>
 								{opt.label}
 							</option>
diff --git a/frontend/src/lib/components/admin/WeeklySchedule.svelte b/frontend/src/lib/components/admin/WeeklySchedule.svelte
index 794d65d..2430f66 100644
--- a/frontend/src/lib/components/admin/WeeklySchedule.svelte
+++ b/frontend/src/lib/components/admin/WeeklySchedule.svelte
@@ -486,7 +486,7 @@
 										class="max-w-[70px] text-sm"
 									>
 										{#each Array(24) as _, hour}
-											{#each TIME15 as min}
+											{#each TIME15 as min (min)}
 												<option value="{String(hour).padStart(2,'0')}:{min}">{String(hour).padStart(2,'0')}:{min}</option>
 											{/each}
 										{/each}
@@ -499,7 +499,7 @@
 										class="max-w-[70px] text-sm"
 									>
 										{#each Array(24) as _, hour}
-											{#each TIME15 as min}
+											{#each TIME15 as min (min)}
 												<option value="{String(hour).padStart(2,'0')}:{min}">{String(hour).padStart(2,'0')}:{min}</option>
 											{/each}
 										{/each}