refactor: add date utility for consistent UTC handling

docs/CONTRIBUTING.md

@@ -569,6 +569,34 @@ Examples:
 - `src/lib/server/db/queries/arrInstances.ts`
 - `src/lib/server/db/queries/jobs.ts`
 
+**Date Handling**
+
+SQLite stores timestamps from `CURRENT_TIMESTAMP` as UTC in the format
+`"YYYY-MM-DD HH:MM:SS"` without a timezone indicator. JavaScript's `Date`
+constructor interprets strings without timezone info as local time, causing
+incorrect display.
+
+Use the shared date utilities in `src/lib/shared/dates.ts`:
+
+```typescript
+import { parseUTC, toUTC } from "$shared/dates";
+
+// Parse SQLite timestamp to Date object (correctly interpreted as UTC)
+const date = parseUTC("2026-01-17 03:21:52"); // Date in UTC
+
+// Normalize to ISO 8601 string with Z suffix
+const iso = toUTC("2026-01-17 03:21:52"); // "2026-01-17T03:21:52Z"
+```
+
+**Never** manually append `'Z'` or manipulate timestamp strings directly. Always
+use these utilities to ensure consistent timezone handling across the codebase.
+
+For SQL queries that compare timestamps, normalize both sides:
+
+```sql
+datetime(replace(replace(timestamp_col, 'T', ' '), 'Z', '')) <= datetime('now')
+```
+
 #### PCD (Profilarr Compliant Database)
 
 PCDs are git repositories containing versioned configuration data—quality

src/lib/shared/dates.ts

@@ -0,0 +1,51 @@
+/**
+ * Date utilities for handling SQLite timestamps
+ *
+ * SQLite stores timestamps from CURRENT_TIMESTAMP as UTC in the format
+ * "YYYY-MM-DD HH:MM:SS" (no timezone indicator). JavaScript's Date constructor
+ * interprets strings without timezone info as local time, causing incorrect
+ * display.
+ *
+ * These utilities normalize SQLite timestamps to proper ISO 8601 format
+ * so JavaScript correctly interprets them as UTC.
+ */
+
+/**
+ * Normalizes a SQLite timestamp to ISO 8601 format with UTC indicator.
+ * Handles both SQLite format ("YYYY-MM-DD HH:MM:SS") and ISO format.
+ *
+ * @param timestamp - SQLite or ISO timestamp string
+ * @returns ISO 8601 formatted string with Z suffix, or null if input is null/undefined
+ *
+ * @example
+ * toUTC("2026-01-17 03:21:52")     // "2026-01-17T03:21:52Z"
+ * toUTC("2026-01-17T03:21:52")     // "2026-01-17T03:21:52Z"
+ * toUTC("2026-01-17T03:21:52Z")    // "2026-01-17T03:21:52Z" (unchanged)
+ * toUTC(null)                      // null
+ */
+export function toUTC(timestamp: string | null | undefined): string | null {
+	if (!timestamp) return null;
+
+	// Already has Z suffix - return as-is
+	if (timestamp.endsWith('Z')) return timestamp;
+
+	// Replace space with T (SQLite format) and add Z
+	return timestamp.replace(' ', 'T') + 'Z';
+}
+
+/**
+ * Parses a SQLite timestamp into a JavaScript Date object.
+ * Normalizes the timestamp to UTC before parsing.
+ *
+ * @param timestamp - SQLite or ISO timestamp string
+ * @returns Date object, or null if input is null/undefined
+ *
+ * @example
+ * parseUTC("2026-01-17 03:21:52")  // Date object in UTC
+ * parseUTC(null)                   // null
+ */
+export function parseUTC(timestamp: string | null | undefined): Date | null {
+	const normalized = toUTC(timestamp);
+	if (!normalized) return null;
+	return new Date(normalized);
+}

src/routes/arr/[id]/upgrades/components/CooldownTracker.svelte

@@ -1,6 +1,7 @@
 <script lang="ts">
 	import { onMount, onDestroy } from 'svelte';
 	import { Clock, Timer, CheckCircle, PauseCircle } from 'lucide-svelte';
+	import { parseUTC } from '$shared/dates';
 
 	export let enabled: boolean;
 	export let schedule: number; // minutes
@@ -20,8 +21,7 @@
 	});
 
 	// Calculate times
-	// Database stores timestamps without timezone - append Z to parse as UTC
+	$: lastRunTime = parseUTC(lastRunAt)?.getTime() ?? null;
-	$: lastRunTime = lastRunAt ? new Date(lastRunAt.endsWith('Z') ? lastRunAt : lastRunAt + 'Z').getTime() : null;
 	$: scheduleMs = schedule * 60 * 1000;
 	$: nextRunTime = lastRunTime ? lastRunTime + scheduleMs : null;
 	$: timeUntilNext = nextRunTime ? nextRunTime - now : null;
@@ -49,14 +49,10 @@
 		return `${seconds}s`;
 	}
 
-	// Parse timestamp - append Z if needed to treat as UTC
-	function parseTimestamp(str: string): Date {
-		return new Date(str.endsWith('Z') ? str : str + 'Z');
-	}
-
 	// Format absolute time
 	function formatTime(isoString: string): string {
-		const date = parseTimestamp(isoString);
+		const date = parseUTC(isoString);
+		if (!date) return '-';
 		return date.toLocaleTimeString('en-US', {
 			hour: 'numeric',
 			minute: '2-digit',
@@ -65,7 +61,8 @@
 	}
 
 	function formatDate(isoString: string): string {
-		const date = parseTimestamp(isoString);
+		const date = parseUTC(isoString);
+		if (!date) return '-';
 		const today = new Date();
 		const yesterday = new Date(today);
 		yesterday.setDate(yesterday.getDate() - 1);

src/routes/databases/+page.svelte

@@ -13,6 +13,7 @@
 	import SearchAction from '$ui/actions/SearchAction.svelte';
 	import { createSearchStore } from '$stores/search';
 	import { alertStore } from '$alerts/store';
+	import { parseUTC } from '$shared/dates';
 	import type { PageData } from './$types';
 	import type { Column } from '$ui/table/types';
 	import type { DatabaseInstance } from '$db/queries/databaseInstances.ts';
@@ -66,8 +67,14 @@
 
 	// Format last synced date
 	function formatLastSynced(date: string | null): string {
-		if (!date) return 'Never';
+		const d = parseUTC(date);
-		return new Date(date).toLocaleDateString();
+		if (!d) return 'Never';
+		return d.toLocaleString(undefined, {
+			month: 'short',
+			day: 'numeric',
+			hour: 'numeric',
+			minute: '2-digit'
+		});
 	}
 
 	// Handle row click - navigate to database details

src/routes/delay-profiles/[databaseId]/views/TableView.svelte

@@ -5,12 +5,13 @@
 	import { Tag, Clock, Zap, Shield, Calendar } from 'lucide-svelte';
 	import { goto } from '$app/navigation';
 	import { page } from '$app/stores';
+	import { parseUTC } from '$shared/dates';
 
 	export let profiles: DelayProfileTableRow[];
 
 	function formatDate(dateString: string): string {
-		// SQLite stores timestamps without timezone info, treat as UTC
+		const date = parseUTC(dateString);
-		const date = new Date(dateString + 'Z');
+		if (!date) return '-';
 		return date.toLocaleString(undefined, {
 			year: 'numeric',
 			month: 'short',

src/routes/regular-expressions/[databaseId]/views/TableView.svelte

@@ -6,12 +6,13 @@
 	import { marked } from 'marked';
 	import { goto } from '$app/navigation';
 	import { page } from '$app/stores';
+	import { parseUTC } from '$shared/dates';
 
 	export let expressions: RegularExpressionTableRow[];
 
 	function formatDate(dateString: string): string {
-		// SQLite stores timestamps without timezone info, treat as UTC
+		const date = parseUTC(dateString);
-		const date = new Date(dateString + 'Z');
+		if (!date) return '-';
 		return date.toLocaleString(undefined, {
 			year: 'numeric',
 			month: 'short',

src/routes/settings/notifications/components/NotificationHistory.svelte

@@ -1,14 +1,14 @@
 <script lang="ts">
 	import { Bell } from 'lucide-svelte';
+	import { parseUTC } from '$shared/dates';
 	import type { NotificationHistoryRecord } from '$db/queries/notificationHistory.ts';
 
 	export let history: NotificationHistoryRecord[];
 	export let services: Array<{ id: string; name: string }>;
 
 	function formatDateTime(date: string): string {
-		// SQLite stores as UTC without timezone indicator, append Z to parse correctly
+		const d = parseUTC(date);
-		const utcDate = date.endsWith('Z') ? date : date.replace(' ', 'T') + 'Z';
+		return d ? d.toLocaleString() : '-';
-		return new Date(utcDate).toLocaleString();
 	}
 
 	function getServiceName(serviceId: string): string {