Add 'Start week on' setting (Monday default / Sunday) for daily and tasks calendars

src/lib/api.ts

@@ -215,6 +215,7 @@ export async function setNotebookIcon(
 export async function setGeneralSettings(
   compactNotes: boolean,
   timeFormat: string,
+  weekStart: string,
   gpuAcceleration: boolean,
   autostart: boolean,
   pdfPreview: boolean,
@@ -232,6 +233,7 @@ export async function setGeneralSettings(
   return invoke("set_general_settings", {
     compactNotes,
     timeFormat,
+    weekStart,
     gpuAcceleration,
     autostart,
     pdfPreview,

src/lib/components/NoteList.svelte

@@ -64,14 +64,15 @@
 	let dailyDates = $state<Set<string>>(new Set());
 
 	const calMonthNames = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'];
-	const calDayNames = ['Mo', 'Tu', 'We', 'Th', 'Fr', 'Sa', 'Su'];
+	// 0 = Sunday, 1 = Monday (default). Day names + grid offset follow the setting.
+	const weekStartsOn = $derived($appConfig?.week_start === 'sunday' ? 0 : 1);
+	const DOW = ['Su', 'Mo', 'Tu', 'We', 'Th', 'Fr', 'Sa'];
+	const calDayNames = $derived([...DOW.slice(weekStartsOn), ...DOW.slice(0, weekStartsOn)]);
 
 	function calDays(): Array<{ day: number; date: string; current: boolean }> {
 		const first = new Date(calYear, calMonth, 1);
 		const lastDay = new Date(calYear, calMonth + 1, 0).getDate();
-		// Monday=0 offset
-		let startDow = first.getDay() - 1;
-		if (startDow < 0) startDow = 6;
+		const startDow = (first.getDay() - weekStartsOn + 7) % 7;
 		const cells: Array<{ day: number; date: string; current: boolean }> = [];
 		for (let i = 0; i < startDow; i++) cells.push({ day: 0, date: '', current: false });
 		for (let d = 1; d <= lastDay; d++) {

src/lib/components/SettingsPanel.svelte

@@ -460,6 +460,7 @@
 	let showNoteDates = $state($appConfig?.show_note_dates ?? true);
 	let restoreLastSession = $state($appConfig?.restore_last_session ?? false);
 	let timeFormat = $state($appConfig?.time_format ?? 'relative');
+	let weekStart = $state($appConfig?.week_start ?? 'monday');
 	let gpuAcceleration = $state($appConfig?.gpu_acceleration ?? true);
 	let autostart = $state($appConfig?.autostart ?? false);
 
@@ -517,6 +518,7 @@
 			$appConfig.show_note_dates = showNoteDates;
 			$appConfig.restore_last_session = restoreLastSession;
 			$appConfig.time_format = timeFormat;
+			$appConfig.week_start = weekStart;
 			$appConfig.gpu_acceleration = gpuAcceleration;
 			$appConfig.autostart = autostart;
 			$appConfig.pdf_preview = pdfPreview;
@@ -529,7 +531,7 @@
 			$appConfig.close_to_tray = closeToTray;
 			$appConfig.enable_wiki_links = enableWikiLinks;
 		}
-		setGeneralSettings(compactNotes, timeFormat, gpuAcceleration, autostart, pdfPreview, pdfHeight, titleMode, hideTitleInBody, showLineNumbers, defaultViewMode, showTrayIcon, closeToTray, enableWikiLinks, showNoteDates, restoreLastSession)
+		setGeneralSettings(compactNotes, timeFormat, weekStart, gpuAcceleration, autostart, pdfPreview, pdfHeight, titleMode, hideTitleInBody, showLineNumbers, defaultViewMode, showTrayIcon, closeToTray, enableWikiLinks, showNoteDates, restoreLastSession)
 			.catch((e) => console.error('Failed to save general settings:', e));
 	}
 
@@ -653,6 +655,7 @@
 			showNoteDates = $appConfig.show_note_dates ?? true;
 			restoreLastSession = $appConfig.restore_last_session ?? false;
 			timeFormat = $appConfig.time_format ?? 'relative';
+			weekStart = $appConfig.week_start ?? 'monday';
 			gpuAcceleration = $appConfig.gpu_acceleration ?? true;
 			autostart = $appConfig.autostart ?? false;
 			pdfPreview = $appConfig.pdf_preview ?? false;
@@ -790,6 +793,14 @@
 								</div>
 							</div>
 
+							<div class="settings-section">
+								<h3>Start week on</h3>
+								<div class="setting-options">
+									<button class="option-btn" class:active={weekStart === 'monday'} onclick={() => { weekStart = 'monday'; saveGeneralSettings(); }}>Monday</button>
+									<button class="option-btn" class:active={weekStart === 'sunday'} onclick={() => { weekStart = 'sunday'; saveGeneralSettings(); }}>Sunday</button>
+								</div>
+							</div>
+
 							{#if isMobile}
 							<div class="settings-section">
 								<h3>Vault</h3>

src/lib/components/TasksView.svelte

@@ -3,7 +3,7 @@
 	import { listen } from '@tauri-apps/api/event';
 	import { getTasks } from '$lib/api';
 	import { debounce } from '$lib/utils/debounce';
-	import { tasksLayout } from '$lib/stores/app';
+	import { tasksLayout, appConfig } from '$lib/stores/app';
 	import { isAndroid } from '$lib/platform';
 	import type { TaskItem, FileEvent } from '$lib/types';
 
@@ -104,7 +104,10 @@
 	let selectedDate = $state(today);
 
 	const calMonthNames = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'];
-	const calDayNames = ['Mo', 'Tu', 'We', 'Th', 'Fr', 'Sa', 'Su'];
+	// 0 = Sunday, 1 = Monday (default). Day names + grid offset follow the setting.
+	const weekStartsOn = $derived($appConfig?.week_start === 'sunday' ? 0 : 1);
+	const DOW = ['Su', 'Mo', 'Tu', 'We', 'Th', 'Fr', 'Sa'];
+	const calDayNames = $derived([...DOW.slice(weekStartsOn), ...DOW.slice(0, weekStartsOn)]);
 
 	// Calendar tasks share the list's hide-completed filter (no sort).
 	const calBase = $derived(tasks.filter((t) => !hideCompleted || !t.completed));
@@ -133,8 +136,7 @@
 	);
 
 	function calDays() {
-		// Monday-first: shift so Mon=0 ... Sun=6
-		const firstWeekday = (new Date(calYear, calMonth, 1).getDay() + 6) % 7;
+		const firstWeekday = (new Date(calYear, calMonth, 1).getDay() - weekStartsOn + 7) % 7;
 		const lastDate = new Date(calYear, calMonth + 1, 0).getDate();
 		const cells: { day: number; date: string; current: boolean }[] = [];
 		for (let i = 0; i < firstWeekday; i++) cells.push({ day: 0, date: '', current: false });

src/lib/types.ts

@@ -58,6 +58,7 @@ export interface AppConfig {
   compact_notes: boolean;
   show_note_dates: boolean;
   time_format: string;
+  week_start: string;
   gpu_acceleration: boolean;
   autostart: boolean;
   pdf_preview: boolean;