diff --git a/src/app-state.ts b/src/app-state.ts
index 8b0beb3..d3de814 100644
--- a/src/app-state.ts
+++ b/src/app-state.ts
@@ -60,10 +60,14 @@ export function goToToday(): void {
   setDate(todayIso());
 }
 
-export function shiftDate(days: number): void {
-  const d = new Date(`${state.date}T00:00:00Z`);
+export function addDays(date: string, days: number): string {
+  const d = new Date(`${date}T00:00:00Z`);
   d.setUTCDate(d.getUTCDate() + days);
-  setDate(d.toISOString().slice(0, 10));
+  return d.toISOString().slice(0, 10);
+}
+
+export function shiftDate(days: number): void {
+  setDate(addDays(state.date, days));
 }
 
 export function setSelectedHour(hourId: HourId): void {
diff --git a/src/router.ts b/src/router.ts
index 9d96434..b8c8046 100644
--- a/src/router.ts
+++ b/src/router.ts
@@ -1,4 +1,4 @@
-import { getState, setDate, setSelectedHour, subscribe } from './app-state';
+import { getState, setDate, setSelectedHour, setLanguages, subscribe, type AppState } from './app-state';
 import { HOUR_IDS, type HourId } from './hours/types';
 
 // Real paths (reground.org/vu/2026-08-09/prime), not hash routing — the
@@ -10,37 +10,55 @@ function isHourId(value: string): value is HourId {
   return (HOUR_IDS as readonly string[]).includes(value);
 }
 
-function parseLocation(): { date?: string; hour?: HourId } {
+function parseLanguages(value: string | null): AppState['languages'] | undefined {
+  if (!value) return undefined;
+  const langs = value.split(',').filter(Boolean);
+  if (langs.length === 1) return [langs[0]!];
+  if (langs.length === 2) return [langs[0]!, langs[1]!];
+  return undefined;
+}
+
+function parseLocation(): { date?: string; hour?: HourId; languages?: AppState['languages'] } {
   const path = window.location.pathname;
   if (!path.startsWith(BASE)) return {};
   const [date, hour] = path.slice(BASE.length).split('/').filter(Boolean);
+  const languages = parseLanguages(new URLSearchParams(window.location.search).get('lang'));
   return {
     date: date && /^\d{4}-\d{2}-\d{2}$/.test(date) ? date : undefined,
     hour: hour && isHourId(hour) ? hour : undefined,
+    languages,
   };
 }
 
-function urlFor(date: string, hour: HourId): string {
-  return `${BASE}${date}/${hour}`;
+/** Exported for reuse by day-nav/bilingual-toggle so they can render real
+ * `<a href>` links (right-click / open-in-new-tab / copy-link) instead of
+ * reimplementing this path-building logic. */
+export function urlFor(date: string, hour: HourId, languages: AppState['languages']): string {
+  const base = `${BASE}${date}/${hour}`;
+  // Omit the query string for the default single-English case to keep the
+  // common-case URL clean.
+  if (languages.length === 1 && languages[0] === 'en') return base;
+  return `${base}?lang=${languages.join(',')}`;
 }
 
 let lastUrl = '';
 
 function pushUrl(): void {
-  const { date, selectedHour } = getState();
-  const url = urlFor(date, selectedHour);
+  const { date, selectedHour, languages } = getState();
+  const url = urlFor(date, selectedHour, languages);
   if (url === lastUrl) return;
   lastUrl = url;
   window.history.pushState(null, '', url);
 }
 
 export function initRouter(): void {
-  const { date, hour } = parseLocation();
+  const { date, hour, languages } = parseLocation();
   if (date) setDate(date);
   if (hour) setSelectedHour(hour);
+  if (languages) setLanguages(languages);
 
-  const { date: currentDate, selectedHour } = getState();
-  lastUrl = urlFor(currentDate, selectedHour);
+  const { date: currentDate, selectedHour, languages: currentLanguages } = getState();
+  lastUrl = urlFor(currentDate, selectedHour, currentLanguages);
   window.history.replaceState(null, '', lastUrl);
 
   subscribe(() => pushUrl());
@@ -49,8 +67,9 @@ export function initRouter(): void {
     const parsed = parseLocation();
     // Set lastUrl first so the notify() inside setDate/setSelectedHour below
     // doesn't turn this back-navigation into a new forward pushState.
-    lastUrl = window.location.pathname;
+    lastUrl = window.location.pathname + window.location.search;
     if (parsed.date) setDate(parsed.date);
     if (parsed.hour) setSelectedHour(parsed.hour);
+    if (parsed.languages) setLanguages(parsed.languages);
   });
 }
diff --git a/src/ui/bilingual-toggle.ts b/src/ui/bilingual-toggle.ts
index 548bc1d..cc1fd54 100644
--- a/src/ui/bilingual-toggle.ts
+++ b/src/ui/bilingual-toggle.ts
@@ -1,4 +1,5 @@
 import { getState, setLanguages, type AppState } from '../app-state';
+import { urlFor } from '../router';
 
 // Hardcoded to en/la since those are the only languages with any data so
 // far. The two-language ceiling (never three+ columns) is the real
@@ -11,21 +12,28 @@ const OPTIONS: { label: string; languages: AppState['languages'] }[] = [
 ];
 
 export function renderLanguageToggle(container: HTMLElement): void {
-  const { languages } = getState();
+  const { date, selectedHour, languages } = getState();
   const current = languages.join('+');
 
   container.innerHTML = `
     <div class="language-toggle" role="group" aria-label="Display language">
       ${OPTIONS.map((opt) => {
         const isActive = opt.languages.join('+') === current;
-        return `<button type="button" class="lang-btn${isActive ? ' is-active' : ''}" data-langs="${opt.languages.join(',')}">${opt.label}</button>`;
+        const url = urlFor(date, selectedHour, opt.languages);
+        return `<a href="${url}" class="lang-btn${isActive ? ' is-active' : ''}" data-langs="${opt.languages.join(',')}">${opt.label}</a>`;
       }).join('')}
     </div>
   `;
 
-  container.querySelectorAll<HTMLButtonElement>('[data-langs]').forEach((btn) => {
-    btn.addEventListener('click', () => {
-      const langs = btn.dataset.langs!.split(',') as AppState['languages'];
+  container.querySelectorAll<HTMLAnchorElement>('[data-langs]').forEach((link) => {
+    link.addEventListener('click', (event) => {
+      // Let modifier/middle clicks fall through to normal browser navigation
+      // (open in new tab, etc.) — only plain left-clicks are SPA-routed.
+      if (event.defaultPrevented || event.button !== 0 || event.metaKey || event.ctrlKey || event.shiftKey || event.altKey) {
+        return;
+      }
+      event.preventDefault();
+      const langs = link.dataset.langs!.split(',') as AppState['languages'];
       setLanguages(langs);
     });
   });
diff --git a/src/ui/day-nav.ts b/src/ui/day-nav.ts
index 4076dd7..0f454c6 100644
--- a/src/ui/day-nav.ts
+++ b/src/ui/day-nav.ts
@@ -1,6 +1,7 @@
-import { getState, shiftDate, goToToday } from '../app-state';
+import { getState, shiftDate, goToToday, addDays, todayIso } from '../app-state';
 import { resolveDay } from '../calendar';
 import { getDayLabel } from '../calendar/day-label';
+import { urlFor } from '../router';
 import { formatDateLong, renderBilingual } from './format';
 
 /** Renders navigation plus the merged "when" header: the civil date/
@@ -11,22 +12,37 @@ import { formatDateLong, renderBilingual } from './format';
  * hour on a given date), so it's resolved directly here via `resolveDay`
  * rather than through any particular hour's `resolveOrdo`. */
 export function renderDayNav(container: HTMLElement): void {
-  const { date, languages } = getState();
+  const { date, selectedHour, languages } = getState();
   const day = resolveDay(date);
   const dateLabel = formatDateLong(date);
   const dayLabel = getDayLabel(day);
+  const prevUrl = urlFor(addDays(date, -1), selectedHour, languages);
+  const nextUrl = urlFor(addDays(date, 1), selectedHour, languages);
+  const todayUrl = urlFor(todayIso(), selectedHour, languages);
   container.innerHTML = `
     <nav class="day-nav" aria-label="Day navigation">
-      <button type="button" class="day-nav-btn" data-action="prev" aria-label="Previous day">&larr;</button>
-      <button type="button" class="day-nav-btn day-nav-today" data-action="today">Today</button>
+      <a href="${prevUrl}" class="day-nav-btn" data-action="prev" aria-label="Previous day">&larr;</a>
+      <a href="${todayUrl}" class="day-nav-btn day-nav-today" data-action="today">Today</a>
       <div class="day-nav-header">
         ${renderBilingual(dateLabel, languages, 'day-nav-date')}
         ${renderBilingual(dayLabel, languages, 'day-nav-label')}
       </div>
-      <button type="button" class="day-nav-btn" data-action="next" aria-label="Next day">&rarr;</button>
+      <a href="${nextUrl}" class="day-nav-btn" data-action="next" aria-label="Next day">&rarr;</a>
     </nav>
   `;
-  container.querySelector('[data-action="prev"]')?.addEventListener('click', () => shiftDate(-1));
-  container.querySelector('[data-action="next"]')?.addEventListener('click', () => shiftDate(1));
-  container.querySelector('[data-action="today"]')?.addEventListener('click', () => goToToday());
+
+  const bindNav = (action: string, mutate: () => void): void => {
+    container.querySelector<HTMLAnchorElement>(`[data-action="${action}"]`)?.addEventListener('click', (event) => {
+      // Let modifier/middle clicks fall through to normal browser navigation
+      // (open in new tab, etc.) — only plain left-clicks are SPA-routed.
+      if (event.defaultPrevented || (event as MouseEvent).button !== 0 || (event as MouseEvent).metaKey || (event as MouseEvent).ctrlKey || (event as MouseEvent).shiftKey || (event as MouseEvent).altKey) {
+        return;
+      }
+      event.preventDefault();
+      mutate();
+    });
+  };
+  bindNav('prev', () => shiftDate(-1));
+  bindNav('next', () => shiftDate(1));
+  bindNav('today', () => goToToday());
 }
diff --git a/src/ui/hour-list.ts b/src/ui/hour-list.ts
index 34c0581..7a84b37 100644
--- a/src/ui/hour-list.ts
+++ b/src/ui/hour-list.ts
@@ -1,13 +1,21 @@
 import { getState, setSelectedHour } from '../app-state';
-import { HOUR_IDS, resolveOrdo, type HourId } from '../hours';
+import { resolveOrdo, type HourId } from '../hours';
 import { hourLabel } from './format';
 
 const BASE = import.meta.env.BASE_URL;
 
+// Traditional grouping into rows, each starting a "hinge" hour: night
+// office, day hours, evening — rather than one flat wrapped list.
+const HOUR_ROWS: readonly HourId[][] = [
+  ['matins', 'lauds'],
+  ['prime', 'terce', 'sext', 'none'],
+  ['vespers', 'compline'],
+];
+
 export function renderHourList(container: HTMLElement): void {
   const { date, selectedHour } = getState();
 
-  const items = HOUR_IDS.map((hourId) => {
+  const renderItem = (hourId: HourId): string => {
     const ordo = resolveOrdo(hourId, date);
     const isSelected = hourId === selectedHour;
     const isReady = !ordo.notImplemented;
@@ -24,9 +32,12 @@ export function renderHourList(container: HTMLElement): void {
         </a>
       </li>
     `;
-  }).join('');
+  };
 
-  container.innerHTML = `<ul class="hour-list">${items}</ul>`;
+  const separator = '<li class="hour-sep">&nbsp;</li>';
+  const rows = HOUR_ROWS.map((row) => `<ul class="hour-list">${row.map(renderItem).join(separator)}</ul>`).join('');
+
+  container.innerHTML = rows;
 
   container.querySelectorAll<HTMLAnchorElement>('[data-hour]').forEach((link) => {
     link.addEventListener('click', (event) => {
diff --git a/src/ui/styles.css b/src/ui/styles.css
index f8802cf..bbd39f0 100644
--- a/src/ui/styles.css
+++ b/src/ui/styles.css
@@ -198,9 +198,16 @@ button:focus-visible {
   padding: var(--space-3) var(--space-2);
 }
 
+.hour-list-nav {
+  display: flex;
+  flex-direction: column;
+  gap: var(--space-2);
+}
+
 .hour-list {
   display: flex;
   flex-wrap: wrap;
+  gap: var(--space-2);
   list-style: none;
   margin: 0;
   padding: 0;
@@ -239,6 +246,12 @@ button:focus-visible {
   opacity: 0.85;
 }
 
+.hour-sep {
+  display: flex;
+  align-items: center;
+  color: var(--color-border);
+}
+
 .hour-status {
   font-size: 0.7rem;
   text-transform: uppercase;