feat(rezepte)!: liturgical-aware seasonality via date ranges

Replace season: number[] (months 1-12) on Recipe with seasonRanges, a
list of date ranges where each endpoint is either a fixed MM-DD or a
movable liturgical anchor (Easter, Ash Wednesday, Palm Sunday,
Pentecost, Advent I) plus a day offset. The old month list couldn't
express liturgical seasons whose boundaries shift each year (Advent,
Lent, Easter Octave, Christmas Octave) nor sub-month windows.

The shared evaluator resolves anchors against [Y-1, Y, Y+1] so spans
that wrap the calendar year boundary (e.g. christmas + 0 to
christmas + 7) match correctly on both sides. SeasonSelect was
rewritten as a controlled bind:ranges editor with a
fixed/liturgical kind toggle, anchor + offset inputs, per-row
resolved-this-year preview, and preset chips.

Run the one-time migration before deploying:
  pnpm exec vite-node scripts/migrate-season-to-ranges.ts

It coalesces contiguous month runs into single fixed ranges and
merges Dec/Jan wrap into one wrapping range; the new code does not
read the legacy season field, so order matters.

package.json

@@ -1,6 +1,6 @@
 {
 	"name": "homepage",
-	"version": "1.58.1",
+	"version": "1.59.1",
 	"private": true,
 	"type": "module",
 	"scripts": {

scripts/migrate-season-to-ranges.ts

@@ -0,0 +1,107 @@
+/**
+ * One-time migration: convert legacy `season: number[]` (months 1–12) on every
+ * Recipe document to the new `seasonRanges: SeasonRange[]` shape.
+ *
+ * Contiguous months are coalesced into a single range. A wrap across the year
+ * boundary (e.g. months [11, 12, 1, 2]) merges into one wrapping range
+ * Nov 1 → Feb 28; non-contiguous months stay as separate ranges.
+ *
+ * The legacy `season` field is then $unset.
+ *
+ * Run before deploying the new code path:
+ *   pnpm exec vite-node scripts/migrate-season-to-ranges.ts
+ *
+ * Idempotent: a recipe with no `season` field is left untouched.
+ */
+
+import { readFileSync } from 'fs';
+import { resolve } from 'path';
+import mongoose from 'mongoose';
+
+const envPath = resolve(import.meta.dirname ?? '.', '..', '.env');
+const envText = readFileSync(envPath, 'utf-8');
+const mongoMatch = envText.match(/^MONGO_URL="?([^"\n]+)"?/m);
+if (!mongoMatch) { console.error('MONGO_URL not found in .env'); process.exit(1); }
+const MONGO_URL = mongoMatch[1];
+
+const LAST_DAY = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
+
+type FixedRange = { startM: number; endM: number };
+
+/**
+ * Coalesce a set of months (1–12) into contiguous ranges, merging the
+ * year-boundary wrap if both Jan and Dec runs are present.
+ */
+function coalesceMonths(months: number[]): FixedRange[] {
+	const sorted = [...new Set(months.filter(m => Number.isInteger(m) && m >= 1 && m <= 12))].sort((a, b) => a - b);
+	if (sorted.length === 0) return [];
+
+	const runs: FixedRange[] = [];
+	let runStart = sorted[0];
+	let runEnd = sorted[0];
+	for (let i = 1; i < sorted.length; i++) {
+		if (sorted[i] === runEnd + 1) {
+			runEnd = sorted[i];
+		} else {
+			runs.push({ startM: runStart, endM: runEnd });
+			runStart = sorted[i];
+			runEnd = sorted[i];
+		}
+	}
+	runs.push({ startM: runStart, endM: runEnd });
+
+	// Merge the trailing-Dec run into the leading-Jan run so a winter span
+	// like [11,12,1,2] becomes one wrapping Nov→Feb range instead of two.
+	if (runs.length >= 2 && runs[0].startM === 1 && runs[runs.length - 1].endM === 12) {
+		const wrapped = { startM: runs[runs.length - 1].startM, endM: runs[0].endM };
+		return [wrapped, ...runs.slice(1, -1)];
+	}
+	return runs;
+}
+
+function rangeFromRun(run: FixedRange) {
+	return {
+		start: { kind: 'fixed', m: run.startM, d: 1 },
+		end: { kind: 'fixed', m: run.endM, d: LAST_DAY[run.endM - 1] }
+	};
+}
+
+async function main() {
+	await mongoose.connect(MONGO_URL);
+	const Recipe = mongoose.connection.collection('recipes');
+
+	const cursor = Recipe.find({ season: { $exists: true } });
+	let migrated = 0;
+	let skipped = 0;
+
+	while (await cursor.hasNext()) {
+		const doc = await cursor.next() as any;
+		if (!doc) break;
+
+		const months: number[] = Array.isArray(doc.season) ? doc.season : [];
+		const runs = coalesceMonths(months);
+
+		if (runs.length === 0) {
+			await Recipe.updateOne({ _id: doc._id }, { $unset: { season: '' } });
+			skipped++;
+			continue;
+		}
+
+		const seasonRanges = runs.map(rangeFromRun);
+
+		await Recipe.updateOne(
+			{ _id: doc._id },
+			{ $set: { seasonRanges }, $unset: { season: '' } }
+		);
+		migrated++;
+		if (migrated % 25 === 0) console.log(`  migrated ${migrated}…`);
+	}
+
+	console.log(`\nDone. Migrated: ${migrated}. Skipped (empty season): ${skipped}.`);
+	await mongoose.disconnect();
+}
+
+main().catch((e) => {
+	console.error(e);
+	process.exit(1);
+});

src/lib/components/recipes/Card.svelte

@@ -3,10 +3,10 @@ import "$lib/css/shake.css";
 import "$lib/css/icon.css";
 import { onMount } from "svelte";
 import Heart from '@lucide/svelte/icons/heart';
+import { isRecipeInSeason } from '$lib/js/seasonRange';
 
 let {
 	recipe,
-	current_month: currentMonthProp = 0,
 	icon_override = false,
 	search = true,
 	do_margin_right = false,
@@ -17,8 +17,7 @@ let {
 	translationStatus = undefined
 } = $props();
 
-// Make current_month reactive based on icon_override
-let current_month = $derived(icon_override ? recipe.season[0] : currentMonthProp);
+const isInSeason = $derived(icon_override || isRecipeInSeason(recipe));
 
 let isloaded = $state(false);
 
@@ -259,7 +258,7 @@ function preloadHeroImage() {
 			{/if}
 		</div>
 	{/if}
-	{#if icon_override || recipe.season.includes(current_month)}
+	{#if isInSeason}
 		<a href="{routePrefix}/icon/{recipe.icon}" class="icon g-icon-badge">{recipe.icon}</a>
 	{/if}
 	<div class="card_title">

src/lib/components/recipes/CompactCard.svelte

@@ -1,10 +1,10 @@
 <script lang="ts">
 	import "$lib/css/shake.css";
 	import Heart from '@lucide/svelte/icons/heart';
+	import { isRecipeInSeason } from '$lib/js/seasonRange';
 
 	let {
 		recipe,
-		current_month = 0,
 		icon_override = false,
 		isFavorite = false,
 		showFavoriteIndicator = false,
@@ -23,7 +23,7 @@
 
 	const img_color = $derived(recipe.images?.[0]?.color || '');
 
-	const isInSeason = $derived(icon_override || recipe.season?.includes(current_month));
+	const isInSeason = $derived(icon_override || isRecipeInSeason(recipe));
 
 	function activateTransitions(event: MouseEvent) {
 		const img = (event.currentTarget as HTMLElement)?.querySelector('.img-wrap img') as HTMLElement | null;

src/lib/components/recipes/RecipeEditor.svelte

@@ -8,12 +8,12 @@
 
 	let {
 		card_data = $bindable({}),
-		season = $bindable([]),
+		seasonRanges = $bindable([]),
 		ingredients = $bindable([]),
 		instructions = $bindable([])
 	}: {
 		card_data?: any,
-		season?: any[],
+		seasonRanges?: any[],
 		ingredients?: any[],
 		instructions?: any[]
 	} = $props();
@@ -31,7 +31,7 @@
 			method: 'POST',
 			body: JSON.stringify({
 				recipe: {
-					season: season,
+					seasonRanges: seasonRanges,
 					...card_data,
 					images: [{
 						mediapath: short_name + '.webp',
@@ -71,8 +71,8 @@ input.temp{
 
 <input class=temp bind:value={short_name} placeholder="Kurzname"/>
 
-<SeasonSelect></SeasonSelect>
-<button onclick={() => console.log(season)}>PRINTOUT season</button>
+<SeasonSelect bind:ranges={seasonRanges} />
+<button onclick={() => console.log(seasonRanges)}>PRINTOUT season</button>
 
 <h2>Zutaten</h2>
 <CreateIngredientList bind:ingredients={ingredients}></CreateIngredientList>

src/lib/components/recipes/Search.svelte

@@ -4,6 +4,7 @@
     import FilterPanel from './FilterPanel.svelte';
     import { getCategories } from '$lib/js/categories';
     import { m } from '$lib/js/recipesI18n';
+    import { recipeOverlapsMonth } from '$lib/js/seasonRange';
     /** @typedef {import('$lib/js/recipesI18n').RecipesLang} RecipesLang */
 
     // Filter props for different contexts
@@ -85,10 +86,9 @@
                     return false;
                 }
 
-                // Season filter: recipe in any selected season
+                // Season filter: recipe overlaps any selected month
                 if (selectedSeasons.length > 0) {
-                    const recipeSeasons = recipe.season || [];
-                    if (!selectedSeasons.some(s => recipeSeasons.includes(s))) {
+                    if (!selectedSeasons.some(m => recipeOverlapsMonth(recipe, m))) {
                         return false;
                     }
                 }
@@ -117,7 +117,7 @@
                 const matchesCategory = categoryArray.length > 0 ? categoryArray.includes(recipe.category) : false;
                 const matchesTags = selectedTags.length > 0 ? selectedTags.some(tag => (recipe.tags || []).includes(tag)) : false;
                 const matchesIcon = iconArray.length > 0 ? iconArray.includes(recipe.icon) : false;
-                const matchesSeasons = selectedSeasons.length > 0 ? selectedSeasons.some(s => (recipe.season || []).includes(s)) : false;
+                const matchesSeasons = selectedSeasons.length > 0 ? selectedSeasons.some(m => recipeOverlapsMonth(recipe, m)) : false;
                 const matchesFavorites = selectedFavoritesOnly ? recipe.isFavorite : false;
 
                 return matchesCategory || matchesTags || matchesIcon || matchesSeasons || matchesFavorites;

src/lib/components/recipes/SeasonSelect.svelte

@@ -1,102 +1,253 @@
-<script lang=ts>
-import { season } from '$lib/js/season_store.js'
-import {onMount} from "svelte";
-    import {do_on_key} from "./do_on_key";
-let months = ["Januar", "Februar", "März", "April", "Mai", "Juni", "Juli", "August", "September", "Oktober", "November", "Dezember"]
+<script lang="ts">
+	import { formatRangePreview } from '$lib/js/seasonRange';
+	import type { SeasonAnchorKey, SeasonEndpoint, SeasonRange } from '$types/types';
 
+	let { ranges = $bindable<SeasonRange[]>([]) }: { ranges?: SeasonRange[] } = $props();
 
+	const MONTHS_DE = ["Januar", "Februar", "März", "April", "Mai", "Juni", "Juli", "August", "September", "Oktober", "November", "Dezember"];
 
-let season_local: number[] = [];
+	const ANCHOR_LABELS: Record<SeasonAnchorKey, string> = {
+		easter: 'Ostersonntag',
+		'ash-wednesday': 'Aschermittwoch',
+		'palm-sunday': 'Palmsonntag',
+		pentecost: 'Pfingstsonntag',
+		'advent-i': '1. Adventssonntag'
+	};
+	const ANCHOR_KEYS: SeasonAnchorKey[] = ['easter', 'ash-wednesday', 'palm-sunday', 'pentecost', 'advent-i'];
 
-season.subscribe((s: number[]) => {
-	season_local = s;
-});
-
-export function set_season(){
-	let temp: number[] = [];
-	const el = document.getElementById("labels");
-	if (!el) return;
-	for(var i = 0; i < el.children.length; i++){
-		if((el.children[i].children[0].children[0] as HTMLInputElement).checked){
-			temp.push(i+1)
-		}
-	}
-	season.update(() => temp)
+	function commit(next: SeasonRange[]) {
+		ranges = next;
 	}
 
-function write_season(season: number[]){
-	const el = document.getElementById("labels");
-	if (!el) return;
-	for(var i = 0; i < season.length; i++){
-		(el.children[season[i]-1].children[0].children[0] as HTMLInputElement).checked = true;
+	function fixed(m: number, d: number): SeasonEndpoint {
+		return { kind: 'fixed', m, d };
+	}
+	function liturgical(anchor: SeasonAnchorKey, offsetDays = 0): SeasonEndpoint {
+		return { kind: 'liturgical', anchor, offsetDays };
+	}
+
+	function withEndpoint(i: number, which: 'start' | 'end', ep: SeasonEndpoint): SeasonRange[] {
+		return ranges.map((r, idx) => (idx === i ? { ...r, [which]: ep } : r));
+	}
+
+	function addMonthRange(m: number) {
+		const last = new Date(2001, m, 0).getDate();
+		commit([...ranges, { start: fixed(m, 1), end: fixed(m, last) }]);
+	}
+
+	function addPreset(label: string) {
+		const presets: Record<string, SeasonRange> = {
+			lent: { start: liturgical('ash-wednesday', 0), end: liturgical('easter', -1) },
+			'holy-week': { start: liturgical('palm-sunday', 0), end: liturgical('easter', -1) },
+			'easter-octave': { start: liturgical('easter', 0), end: liturgical('easter', 7) },
+			eastertide: { start: liturgical('easter', 0), end: liturgical('pentecost', 0) },
+			advent: { start: liturgical('advent-i', 0), end: fixed(12, 24) },
+			'christmas-octave': { start: fixed(12, 25), end: fixed(1, 1) }
+		};
+		const preset = presets[label];
+		if (preset) {
+			commit([...ranges, { start: { ...preset.start }, end: { ...preset.end } }]);
 		}
 	}
 
-function toggle_checkbox_on_key(event: Event){
-	const target = event.target as HTMLElement;
-	const checkbox = target.querySelector('input[type="checkbox"]') as HTMLInputElement;
-	if (checkbox) checkbox.checked = !checkbox.checked;
+	function removeRange(i: number) {
+		commit(ranges.filter((_, idx) => idx !== i));
 	}
-onMount(() => {
-	write_season(season_local)
-});
 
+	function setEndpointKind(i: number, which: 'start' | 'end', kind: 'fixed' | 'liturgical') {
+		const ep = ranges[i][which];
+		if (kind === ep.kind) return;
+		const next: SeasonEndpoint = kind === 'fixed' ? fixed(1, 1) : liturgical('easter', 0);
+		commit(withEndpoint(i, which, next));
+	}
+
+	function updateFixed(i: number, which: 'start' | 'end', field: 'm' | 'd', value: number) {
+		const ep = ranges[i][which];
+		if (ep.kind !== 'fixed') return;
+		if (Number.isNaN(value)) return;
+		commit(withEndpoint(i, which, { ...ep, [field]: value }));
+	}
+
+	function updateLiturgical(i: number, which: 'start' | 'end', field: 'anchor' | 'offsetDays', value: SeasonAnchorKey | number) {
+		const ep = ranges[i][which];
+		if (ep.kind !== 'liturgical') return;
+		if (field === 'offsetDays' && Number.isNaN(value as number)) return;
+		commit(withEndpoint(i, which, { ...ep, [field]: value }));
+	}
+
+	const currentYear = new Date().getFullYear();
+
+	let selectedMonth = $state<number>(1);
+	let selectedPreset = $state<string>('');
 </script>
+
 <style>
-label{
-	background-color: var(--nord0);
-	color: white;
-	padding: 0.25em 1em;
-	margin-inline: 0.1em;
-	line-height: 2em;
-	border-radius: var(--radius-pill);
-	cursor: pointer;
-	position: relative;
-	transition: var(--transition-fast);
-	user-select: none;
+.season-editor {
+	display: flex;
+	flex-direction: column;
+	gap: 0.75rem;
+	max-width: 720px;
+	margin: 0 auto;
 }
-
-.checkbox_container{
-	transition: var(--transition-fast);
-}
-.checkbox_container:hover,
-.checkbox_container:focus-within
-{
-	transform: scale(1.1,1.1);
-}
-label:hover,
-label:focus-visible
-{
-	background-color: var(--lightblue);
-}
-
-label:has(input:checked){
-	background-color: var(--blue);
-}
-input[type=checkbox],
-input[type=checkbox]::before,
-input[type=checkbox]::after
-{
-	all: unset;
-	user-select: none;
-}
-
-#labels{
+.range-row {
 	display: flex;
 	flex-wrap: wrap;
-	flex-direction: row;
-	justify-content: center;
-	margin-bottom: 1em;
-
+	gap: 0.5rem;
+	align-items: center;
+	padding: 0.6rem 0.75rem;
+	background: var(--color-bg-tertiary);
+	border-radius: var(--radius-md);
+	border: 1px solid var(--color-border);
+}
+.endpoint {
+	display: flex;
+	gap: 0.4rem;
+	align-items: center;
+	flex-wrap: wrap;
+}
+.kind-toggle {
+	display: inline-flex;
+	border-radius: var(--radius-pill);
+	overflow: hidden;
+	background: var(--color-bg-elevated);
+}
+.kind-toggle button {
+	all: unset;
+	padding: 0.2rem 0.7rem;
+	font-size: 0.85rem;
+	cursor: pointer;
+	color: var(--color-text-secondary);
+}
+.kind-toggle button.active {
+	background: var(--color-primary);
+	color: var(--color-text-on-primary);
+}
+.endpoint select,
+.endpoint input[type="number"] {
+	background: var(--color-bg-primary);
+	color: var(--color-text-primary);
+	border: 1px solid var(--color-border);
+	border-radius: var(--radius-sm);
+	padding: 0.2rem 0.4rem;
+	font-size: 0.9rem;
+}
+.endpoint input[type="number"] {
+	width: 4.5em;
+}
+.dash {
+	color: var(--color-text-tertiary);
+	padding: 0 0.25rem;
+}
+.preview {
+	font-size: 0.85rem;
+	color: var(--color-text-tertiary);
+	flex-basis: 100%;
+}
+.remove-btn {
+	all: unset;
+	margin-left: auto;
+	cursor: pointer;
+	color: var(--color-text-secondary);
+	font-size: 1.1rem;
+	padding: 0 0.4rem;
+	border-radius: var(--radius-sm);
+}
+.remove-btn:hover {
+	background: var(--red);
+	color: white;
+}
+.add-bar {
+	display: flex;
+	flex-wrap: wrap;
+	gap: 0.5rem;
+	align-items: center;
+	padding: 0.6rem 0.75rem;
+	background: var(--color-surface);
+	border-radius: var(--radius-md);
+}
+.add-bar select,
+.add-bar button {
+	background: var(--color-bg-tertiary);
+	color: var(--color-text-primary);
+	border: 1px solid var(--color-border);
+	border-radius: var(--radius-sm);
+	padding: 0.3rem 0.6rem;
+	font-size: 0.9rem;
+	cursor: pointer;
+}
+.add-bar button {
+	background: var(--color-primary);
+	color: var(--color-text-on-primary);
+	border-color: var(--color-primary);
+}
+.add-bar button:hover {
+	background: var(--color-primary-hover);
+}
+.empty {
+	color: var(--color-text-tertiary);
+	font-style: italic;
+	font-size: 0.9rem;
+	text-align: center;
+	padding: 0.5rem;
 }
 </style>
 
-<div id=labels>
-{#each months as month}
-	<div class=checkbox_container>
-		<!-- svelte-ignore a11y_no_noninteractive_tabindex -->
-		<!-- svelte-ignore a11y_no_noninteractive_element_interactions -->
-		<label tabindex="0" onkeydown={(event) => do_on_key(event, 'Enter', false, () => {toggle_checkbox_on_key(event)}) } ><input tabindex=-1 type="checkbox" name="checkbox" value="value" onclick={set_season}>{month}</label>
+<div class="season-editor">
+	{#if ranges.length === 0}
+		<div class="empty">Keine Saison-Bereiche – immer verfügbar.</div>
+	{/if}
+
+	{#each ranges as range, i (i)}
+		<div class="range-row">
+			{#each ['start', 'end'] as const as which, wi (which)}
+				{#if wi > 0}
+					<span class="dash">–</span>
+				{/if}
+				<div class="endpoint">
+					<div class="kind-toggle">
+						<button type="button" class:active={range[which].kind === 'fixed'} onclick={() => setEndpointKind(i, which, 'fixed')}>Datum</button>
+						<button type="button" class:active={range[which].kind === 'liturgical'} onclick={() => setEndpointKind(i, which, 'liturgical')}>Liturgisch</button>
+					</div>
+					{#if range[which].kind === 'fixed'}
+						<select value={range[which].m} onchange={(e) => updateFixed(i, which, 'm', parseInt((e.currentTarget as HTMLSelectElement).value))}>
+							{#each MONTHS_DE as name, mi (mi)}
+								<option value={mi + 1}>{name}</option>
+							{/each}
+						</select>
+						<input type="number" min="1" max="31" value={range[which].d} oninput={(e) => updateFixed(i, which, 'd', parseInt((e.currentTarget as HTMLInputElement).value))} />
+					{:else}
+						<select value={range[which].anchor} onchange={(e) => updateLiturgical(i, which, 'anchor', (e.currentTarget as HTMLSelectElement).value as SeasonAnchorKey)}>
+							{#each ANCHOR_KEYS as a (a)}
+								<option value={a}>{ANCHOR_LABELS[a]}</option>
+							{/each}
+						</select>
+						<input type="number" value={range[which].offsetDays} oninput={(e) => updateLiturgical(i, which, 'offsetDays', parseInt((e.currentTarget as HTMLInputElement).value || '0'))} title="Tage Versatz" />
+						<span class="dash">Tage</span>
+					{/if}
 				</div>
 			{/each}
+			<button type="button" class="remove-btn" onclick={() => removeRange(i)} aria-label="Bereich entfernen">×</button>
+			<div class="preview">{currentYear}: {formatRangePreview(range, currentYear, 'de')}</div>
+		</div>
+	{/each}
+
+	<div class="add-bar">
+		<span>Hinzufügen:</span>
+		<select bind:value={selectedMonth}>
+			{#each MONTHS_DE as name, mi (mi)}
+				<option value={mi + 1}>{name}</option>
+			{/each}
+		</select>
+		<button type="button" onclick={() => addMonthRange(selectedMonth)}>Monat</button>
+		<select bind:value={selectedPreset}>
+			<option value="">Liturgisch…</option>
+			<option value="lent">Fastenzeit</option>
+			<option value="holy-week">Karwoche</option>
+			<option value="easter-octave">Osteroktav</option>
+			<option value="eastertide">Osterzeit</option>
+			<option value="advent">Advent</option>
+			<option value="christmas-octave">Weihnachtsoktav</option>
+		</select>
+		<button type="button" disabled={!selectedPreset} onclick={() => { if (selectedPreset) { addPreset(selectedPreset); selectedPreset = ''; } }}>Vorlage</button>
+	</div>
 </div>

src/lib/js/easter.svelte.ts

@@ -64,3 +64,53 @@ export function getLiturgicalSeason(date: Date = new Date()): LiturgicalSeason {
 	if (isLent(date) && date.getDay() !== 0) return 'lent';
 	return null;
 }
+
+import type { SeasonAnchorKey } from '$types/types';
+
+function addDays(d: Date, days: number): Date {
+	const out = new Date(d);
+	out.setDate(out.getDate() + days);
+	return out;
+}
+
+export function computeAshWednesday(year: number): Date {
+	return addDays(computeEaster(year), -46);
+}
+
+export function computePalmSunday(year: number): Date {
+	return addDays(computeEaster(year), -7);
+}
+
+export function computePentecost(year: number): Date {
+	return addDays(computeEaster(year), 49);
+}
+
+/**
+ * First Sunday of Advent: the Sunday on or before December 24, minus 21 days
+ * (i.e. the 4th Sunday before Christmas Day).
+ */
+export function computeAdventI(year: number): Date {
+	const dec24 = new Date(year, 11, 24);
+	const adventIV = addDays(dec24, -dec24.getDay()); // Sunday on or before Dec 24
+	return addDays(adventIV, -21);
+}
+
+const anchorCache = new Map<number, Record<SeasonAnchorKey, Date>>();
+
+/**
+ * Resolved anchor dates for a given civil year. Memoized — the work is cheap
+ * but the season evaluator hits this on every range × every recipe.
+ */
+export function getLiturgicalAnchors(year: number): Record<SeasonAnchorKey, Date> {
+	const cached = anchorCache.get(year);
+	if (cached) return cached;
+	const anchors: Record<SeasonAnchorKey, Date> = {
+		easter: computeEaster(year),
+		'ash-wednesday': computeAshWednesday(year),
+		'palm-sunday': computePalmSunday(year),
+		pentecost: computePentecost(year),
+		'advent-i': computeAdventI(year)
+	};
+	anchorCache.set(year, anchors);
+	return anchors;
+}

src/lib/js/seasonRange.ts

@@ -0,0 +1,118 @@
+import type { SeasonAnchorKey, SeasonEndpoint, SeasonRange } from '$types/types';
+import { getLiturgicalAnchors } from './easter.svelte';
+
+function midnight(d: Date): Date {
+	return new Date(d.getFullYear(), d.getMonth(), d.getDate());
+}
+
+function addDays(d: Date, days: number): Date {
+	const out = new Date(d);
+	out.setDate(out.getDate() + days);
+	return out;
+}
+
+function lastDayOfMonth(year: number, month1to12: number): number {
+	return new Date(year, month1to12, 0).getDate();
+}
+
+function clampDay(year: number, month1to12: number, day: number): number {
+	const last = lastDayOfMonth(year, month1to12);
+	return Math.min(Math.max(day, 1), last);
+}
+
+export function resolveEndpoint(
+	ep: SeasonEndpoint,
+	year: number,
+	anchors: Record<SeasonAnchorKey, Date> = getLiturgicalAnchors(year)
+): Date {
+	if (ep.kind === 'fixed') {
+		return new Date(year, ep.m - 1, clampDay(year, ep.m, ep.d));
+	}
+	return midnight(addDays(anchors[ep.anchor], ep.offsetDays || 0));
+}
+
+/**
+ * Resolve a range against multiple candidate years. A range like
+ * `christmas + 0 → christmas + 7` resolved in year Y produces the interval
+ * Dec 25 Y .. Jan 1 Y+1; resolved in Y-1 produces Dec 25 Y-1 .. Jan 1 Y.
+ * Callers pass `[Y-1, Y, Y+1]` so a test date sees both wrapping intervals.
+ */
+function intervalsForYears(range: SeasonRange, years: number[]): Array<{ start: Date; end: Date }> {
+	const out: Array<{ start: Date; end: Date }> = [];
+	for (const y of years) {
+		const anchors = getLiturgicalAnchors(y);
+		const start = midnight(resolveEndpoint(range.start, y, anchors));
+		const end = midnight(resolveEndpoint(range.end, y, anchors));
+		// If the resolved start is after the resolved end, it is a same-year wrap
+		// (e.g. fixed 12-25 → 01-01 within year Y). Treat as two slices: [start, Dec 31 Y]
+		// and [Jan 1 Y, end]. Most ranges go single-slice — this only catches
+		// the case where the user wrote a same-year wrap with two fixed endpoints.
+		if (start.getTime() <= end.getTime()) {
+			out.push({ start, end });
+		} else {
+			out.push({ start, end: new Date(y, 11, 31) });
+			out.push({ start: new Date(y, 0, 1), end });
+		}
+	}
+	return out;
+}
+
+export function isDateInRange(range: SeasonRange, date: Date): boolean {
+	const d = midnight(date);
+	const y = d.getFullYear();
+	const intervals = intervalsForYears(range, [y - 1, y, y + 1]);
+	const t = d.getTime();
+	for (const iv of intervals) {
+		if (t >= iv.start.getTime() && t <= iv.end.getTime()) return true;
+	}
+	return false;
+}
+
+type RecipeWithRanges = { seasonRanges?: SeasonRange[] };
+
+export function isRecipeInSeason(recipe: RecipeWithRanges, date: Date = new Date()): boolean {
+	const ranges = recipe.seasonRanges;
+	if (!ranges || ranges.length === 0) return false;
+	for (const r of ranges) {
+		if (isDateInRange(r, date)) return true;
+	}
+	return false;
+}
+
+/**
+ * Whether any resolved interval of `range` (across years Y-1, Y, Y+1) overlaps
+ * any day of `month` (1–12) in year Y. Used by the legacy `?season=N` URL filter.
+ */
+export function rangeOverlapsMonth(range: SeasonRange, month: number, year: number = new Date().getFullYear()): boolean {
+	const monthStart = new Date(year, month - 1, 1).getTime();
+	const monthEnd = new Date(year, month - 1, lastDayOfMonth(year, month)).getTime();
+	const intervals = intervalsForYears(range, [year - 1, year, year + 1]);
+	for (const iv of intervals) {
+		if (iv.start.getTime() <= monthEnd && iv.end.getTime() >= monthStart) return true;
+	}
+	return false;
+}
+
+export function recipeOverlapsMonth(recipe: RecipeWithRanges, month: number, year: number = new Date().getFullYear()): boolean {
+	const ranges = recipe.seasonRanges;
+	if (!ranges || ranges.length === 0) return false;
+	for (const r of ranges) {
+		if (rangeOverlapsMonth(r, month, year)) return true;
+	}
+	return false;
+}
+
+/**
+ * Format a resolved range as a human-readable string for the editor preview,
+ * resolved against `year`. Fixed/fixed renders as `Mar 1 – Mar 31`; ranges
+ * touching liturgical anchors include the year for clarity since they shift.
+ */
+export function formatRangePreview(range: SeasonRange, year: number, lang: 'de' | 'en' = 'de'): string {
+	const anchors = getLiturgicalAnchors(year);
+	const start = midnight(resolveEndpoint(range.start, year, anchors));
+	const end = midnight(resolveEndpoint(range.end, year, anchors));
+	const fmt = new Intl.DateTimeFormat(lang === 'en' ? 'en-US' : 'de-DE', { month: 'short', day: 'numeric' });
+	const includesAnchor = range.start.kind === 'liturgical' || range.end.kind === 'liturgical';
+	const yearTag = includesAnchor ? ` (${year})` : '';
+	return `${fmt.format(start)} – ${fmt.format(end)}${yearTag}`;
+}

src/lib/js/season_store.js

@@ -1,3 +0,0 @@
-import { writable } from 'svelte/store';
-
-export const season = writable(/** @type {number[]} */ ([]));

src/lib/offline/db.ts

@@ -1,7 +1,8 @@
 import type { BriefRecipeType, RecipeModelType } from '$types/types';
+import { isRecipeInSeason, recipeOverlapsMonth } from '$lib/js/seasonRange';
 
 const DB_NAME = 'bocken-recipes';
-const DB_VERSION = 2; // Bumped to force recreation of stores
+const DB_VERSION = 3; // v3: dropped multi-entry season index after migration to seasonRanges
 
 const STORE_BRIEF = 'recipes_brief';
 const STORE_FULL = 'recipes_full';
@@ -51,10 +52,12 @@ function openDB(): Promise<IDBDatabase> {
 				db.deleteObjectStore(STORE_META);
 			}
 
-			// Brief recipes store - keyed by short_name for quick lookups
+			// Brief recipes store - keyed by short_name for quick lookups.
+			// Season membership is now driven by date ranges with movable
+			// liturgical anchors that can't be expressed as a static index, so
+			// season filtering loads all rows and runs the shared evaluator.
 			const briefStore = db.createObjectStore(STORE_BRIEF, { keyPath: 'short_name' });
 			briefStore.createIndex('category', 'category', { unique: false });
-			briefStore.createIndex('season', 'season', { unique: false, multiEntry: true });
 
 			// Full recipes store - keyed by short_name
 			db.createObjectStore(STORE_FULL, { keyPath: 'short_name' });
@@ -104,17 +107,14 @@ export async function getBriefRecipesByCategory(category: string): Promise<Brief
 	});
 }
 
-export async function getBriefRecipesBySeason(month: number): Promise<BriefRecipeType[]> {
-	const db = await openDB();
-	return new Promise((resolve, reject) => {
-		const tx = db.transaction(STORE_BRIEF, 'readonly');
-		const store = tx.objectStore(STORE_BRIEF);
-		const index = store.index('season');
-		const request = index.getAll(month);
+export async function getBriefRecipesInSeasonOn(date: Date = new Date()): Promise<BriefRecipeType[]> {
+	const all = await getAllBriefRecipes();
+	return all.filter(r => isRecipeInSeason(r as any, date));
+}
 
-		request.onerror = () => reject(request.error);
-		request.onsuccess = () => resolve(request.result);
-	});
+export async function getBriefRecipesOverlappingMonth(month: number, year: number = new Date().getFullYear()): Promise<BriefRecipeType[]> {
+	const all = await getAllBriefRecipes();
+	return all.filter(r => recipeOverlapsMonth(r as any, month, year));
 }
 
 export async function getBriefRecipesByTag(tag: string): Promise<BriefRecipeType[]> {

src/lib/offline/sync.ts

@@ -241,11 +241,13 @@ async function precacheRecipeData(recipes: BriefRecipeType[]): Promise<void> {
 		dataUrls.push(`/recipes/icon/${encodeURIComponent(icon)}/__data.json`);
 	}
 
-	// Add season subroute data (all 12 months)
+	// Add season subroute data (all 12 months + today's liturgical-aware view)
 	for (let month = 1; month <= 12; month++) {
 		dataUrls.push(`/rezepte/season/${month}/__data.json`);
 		dataUrls.push(`/recipes/season/${month}/__data.json`);
 	}
+	dataUrls.push(`/rezepte/season/__data.json`);
+	dataUrls.push(`/recipes/season/__data.json`);
 
 	// Send message to service worker to cache these URLs
 	if (dataUrls.length > 0) {

src/lib/server/recipeHelpers.ts

@@ -20,8 +20,8 @@ export function briefQueryConfig(recipeLang: string) {
 		prefix: en ? 'translations.en.' : '',
 		/** Projection for brief list queries */
 		projection: en
-			? '_id translations.en short_name images season icon'
-			: 'name short_name images tags category icon description season',
+			? '_id translations.en short_name images seasonRanges icon'
+			: 'name short_name images tags category icon description seasonRanges',
 	};
 }
 
@@ -44,7 +44,7 @@ export function toBrief(recipe: RecipeModelType, recipeLang: string): BriefRecip
 			category: en?.category ?? '',
 			icon: recipe.icon,
 			description: en?.description,
-			season: recipe.season || [],
+			seasonRanges: recipe.seasonRanges || [],
 			germanShortName: recipe.short_name,
 		} as unknown as BriefRecipeType;
 	}

src/models/Recipe.ts

@@ -17,7 +17,25 @@ const RecipeSchema = new mongoose.Schema(
     description: {type: String, required: true},
     note: {type: String},
     tags : [String],
-    season : [Number],
+    seasonRanges: [{
+      _id: false,
+      start: {
+        _id: false,
+        kind: { type: String, enum: ['fixed', 'liturgical'], required: true },
+        m: { type: Number },
+        d: { type: Number },
+        anchor: { type: String, enum: ['easter', 'ash-wednesday', 'palm-sunday', 'pentecost', 'advent-i'] },
+        offsetDays: { type: Number, default: 0 },
+      },
+      end: {
+        _id: false,
+        kind: { type: String, enum: ['fixed', 'liturgical'], required: true },
+        m: { type: Number },
+        d: { type: Number },
+        anchor: { type: String, enum: ['easter', 'ash-wednesday', 'palm-sunday', 'pentecost', 'advent-i'] },
+        offsetDays: { type: Number, default: 0 },
+      },
+    }],
     baking: { temperature: {type:String, default: ""},
 	      length: {type:String, default: ""},
 	      mode: {type:String, default: ""},
@@ -198,7 +216,7 @@ const RecipeSchema = new mongoose.Schema(
 
 // Indexes for efficient querying
 RecipeSchema.index({ short_name: 1 });
-RecipeSchema.index({ season: 1 });
+RecipeSchema.index({ 'seasonRanges.start.anchor': 1 });
 RecipeSchema.index({ "translations.en.short_name": 1 });
 RecipeSchema.index({ "translations.en.translationStatus": 1 });
 

src/routes/[recipeLang=recipeLang]/+page.server.ts

@@ -1,9 +1,9 @@
 import type { PageServerLoad } from "./$types";
 import { getUserFavorites, addFavoriteStatusToRecipes } from "$lib/server/favorites";
+import { isRecipeInSeason } from "$lib/js/seasonRange";
 
 export const load: PageServerLoad = async ({ fetch, locals, params }) => {
     const apiBase = `/api/${params.recipeLang}`;
-    const currentMonth = new Date().getMonth() + 1;
     const session = locals.session ?? await locals.auth();
 
     const [res_all_brief, userFavorites] = await Promise.all([
@@ -12,8 +12,8 @@ export const load: PageServerLoad = async ({ fetch, locals, params }) => {
     ]);
 
     const all_brief = addFavoriteStatusToRecipes(res_all_brief, userFavorites);
-    // Derive seasonal subset from all_brief instead of a separate DB query
-    const season = all_brief.filter((r: any) => r.season?.includes(currentMonth) && r.icon !== '🍽️');
+    const today = new Date();
+    const season = all_brief.filter((r: any) => r.icon !== '🍽️' && isRecipeInSeason(r, today));
 
     return {
         season,

src/routes/[recipeLang=recipeLang]/+page.svelte

@@ -11,7 +11,6 @@
 	let { data } = $props<{ data: PageData }>();
 	const lang = $derived(data.lang as RecipesLang);
 	const t = $derived(m[lang]);
-	let current_month = new Date().getMonth() + 1;
 
 	// Search state
 	let matchedRecipeIds = $state(new Set());
@@ -448,7 +447,6 @@
 					{#each visibleRecipes as recipe, i (recipe._id)}
 						<CompactCard
 							{recipe}
-							{current_month}
 							isFavorite={recipe.isFavorite}
 							showFavoriteIndicator={!!data.session?.user}
 							loading_strat={i < 12 ? "eager" : "lazy"}
@@ -481,7 +479,6 @@
 		{#each visibleRecipes as recipe, i (recipe._id)}
 			<CompactCard
 				{recipe}
-				{current_month}
 				isFavorite={recipe.isFavorite}
 				showFavoriteIndicator={!!data.session?.user}
 				loading_strat={i < 12 ? "eager" : "lazy"}

src/routes/[recipeLang=recipeLang]/+page.ts

@@ -1,6 +1,6 @@
 import { browser } from '$app/environment';
 import { isOffline, canUseOfflineData } from '$lib/offline/helpers';
-import { getAllBriefRecipes, getBriefRecipesBySeason, isOfflineDataAvailable } from '$lib/offline/db';
+import { getAllBriefRecipes, getBriefRecipesInSeasonOn, isOfflineDataAvailable } from '$lib/offline/db';
 import { rand_array } from '$lib/js/randomize';
 import type { PageLoad } from './$types';
 
@@ -24,11 +24,9 @@ export const load: PageLoad = async ({ data }) => {
 		try {
 			const hasOfflineData = await isOfflineDataAvailable();
 			if (hasOfflineData) {
-				const currentMonth = new Date().getMonth() + 1;
-
 				const [allBrief, seasonRecipes] = await Promise.all([
 					getAllBriefRecipes(),
-					getBriefRecipesBySeason(currentMonth)
+					getBriefRecipesInSeasonOn(new Date())
 				]);
 
 				return {

src/routes/[recipeLang=recipeLang]/[name]/+page.svelte

@@ -9,7 +9,7 @@
 	import IngredientsPage from '$lib/components/recipes/IngredientsPage.svelte';
 	import TitleImgParallax from '$lib/components/recipes/TitleImgParallax.svelte';
 	import { afterNavigate } from '$app/navigation';
-    	import {season} from '$lib/js/season_store';
+	import { formatRangePreview, resolveEndpoint } from '$lib/js/seasonRange';
 	import RecipeNote from '$lib/components/recipes/RecipeNote.svelte';
 	import FavoriteButton from '$lib/components/FavoriteButton.svelte';
 	import { onDestroy } from 'svelte';
@@ -53,44 +53,15 @@
 		? ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"]
 		: ["Januar", "Februar", "März", "April", "Mai", "Juni", "Juli", "August", "September", "Oktober", "November", "Dezember"]);
 
-	function season_intervals() {
-		// Guard against missing season data (can happen in offline mode)
-		if (!data.season || !Array.isArray(data.season) || data.season.length === 0) {
-			return [];
-		}
-
-		let interval_arr = []
-
-		let start_i = 0
-		for(var i = 12; i > 0; i--){
-			if(data.season.includes(i)){
-				start_i = data.season.indexOf(i);
-			}
-			else{
-				break
-			}
-		}
-
-		var start = data.season[start_i]
-		var end_i: number = start_i
-		const len = data.season.length
-		for(var i = 0; i < len -1; i++){
-			if(data.season.includes((start + i) %12 + 1)){
-				end_i = (start_i + i + 1) % len
-			}
-			else{
-	  			interval_arr.push([start, data.season[end_i]])
-				start = data.season[(start + i + 1) % len]
-			}
-
-		}
-		if(interval_arr.length == 0){
-	  		interval_arr.push([start, data.season[end_i]])
-		}
-
-		return interval_arr
-	}
-	const season_iv = $derived(season_intervals());
+	const seasonRangeChips = $derived.by(() => {
+		const ranges = data.seasonRanges;
+		if (!ranges || !Array.isArray(ranges) || ranges.length === 0) return [];
+		const year = new Date().getFullYear();
+		return ranges.map((r: any) => ({
+			label: formatRangePreview(r, year, isEnglish ? 'en' : 'de'),
+			month: resolveEndpoint(r.start, year).getMonth() + 1
+		}));
+	});
 
 	const display_date = $derived(data.updatedAt ? new Date(data.updatedAt) : new Date(data.dateCreated));
 	const options: Intl.DateTimeFormatOptions = {
@@ -318,17 +289,12 @@ h2{
 		{#if data.preamble}
 			<p>{@html data.preamble}</p>
 		{/if}
-		{#if season_iv.length > 0}
+		{#if seasonRangeChips.length > 0}
 			<div class=tags>
 				<h2>{labels.season}</h2>
-				{#each season_iv as season}
-					<a class="g-tag" href={resolve('/[recipeLang=recipeLang]/season/[month]', { recipeLang: data.recipeLang, month: String(season[0]) })}>
-						{#if season[0]}
-							{months[season[0] - 1]}
-						{/if}
-						{#if season[1]}
-							- {months[season[1] - 1]}
-						{/if}
+				{#each seasonRangeChips as chip}
+					<a class="g-tag" href={resolve('/[recipeLang=recipeLang]/season/[month]', { recipeLang: data.recipeLang, month: String(chip.month) })}>
+						{chip.label}
 					</a>
 				{/each}
 			</div>

src/routes/[recipeLang=recipeLang]/add/+page.svelte

@@ -24,15 +24,11 @@
 	let showTranslationWorkflow = $state(false);
 	let translationData: any = $state(null);
 
-	// Season store
-	import { season } from '$lib/js/season_store';
+	// Season ranges (controlled by SeasonSelect via bind:ranges)
+	import type { SeasonRange } from '$types/types';
 	import { portions } from '$lib/js/portions_store';
 
-	season.update(() => []);
-	let season_local = $state<number[]>([]);
-	season.subscribe((s) => {
-		season_local = s;
-	});
+	let season_local = $state<SeasonRange[]>([]);
 
 	let portions_local = $state("");
 	portions.update(() => "");
@@ -73,27 +69,12 @@
 	let submitting = $state(false);
 	let formElement: HTMLFormElement;
 
-	// Get season data from checkboxes
-	function get_season(): number[] {
-		const season: number[] = [];
-		const el = document.getElementById("labels");
-		if (!el) return season;
-
-		for (let i = 0; i < el.children.length; i++) {
-			const checkbox = el.children[i].children[0].children[0] as HTMLInputElement;
-			if (checkbox?.checked) {
-				season.push(i + 1);
-			}
-		}
-		return season;
-	}
-
 	// Prepare German recipe data - use $derived to prevent infinite effect loops
 	let germanRecipeData = $derived({
 		...card_data,
 		...add_info,
 		images: selected_image_file ? [{ mediapath: 'pending', alt: "", caption: "" }] : [],
-		season: season_local,
+		seasonRanges: season_local,
 		short_name: short_name.trim(),
 		portions: portions_local,
 		datecreated: new Date(),
@@ -337,7 +318,7 @@ button.action_button {
 	<input type="hidden" name="ingredients_json" value={JSON.stringify(ingredients)} />
 	<input type="hidden" name="instructions_json" value={JSON.stringify(instructions)} />
 	<input type="hidden" name="add_info_json" value={JSON.stringify(add_info)} />
-	<input type="hidden" name="season" value={JSON.stringify(season_local)} />
+	<input type="hidden" name="seasonRanges" value={JSON.stringify(season_local)} />
 	<input type="hidden" name="tags" value={JSON.stringify(card_data.tags)} />
 
 	<!-- Translation data (added after approval) -->
@@ -425,7 +406,7 @@ button.action_button {
 
 			<div class="tags">
 				<h4>Saison:</h4>
-				<SeasonSelect />
+				<SeasonSelect bind:ranges={season_local} />
 			</div>
 		</div>
 	</div>

src/routes/[recipeLang=recipeLang]/admin/untranslated/+page.svelte

@@ -4,7 +4,6 @@
 	import CompactCard from '$lib/components/recipes/CompactCard.svelte';
 
 	let { data } = $props<{ data: PageData }>();
-	let current_month = new Date().getMonth() + 1;
 
 	// Calculate statistics
 	const stats = $derived.by(() => {
@@ -161,7 +160,6 @@ h1 {
 			<div class="card-wrapper">
 				<CompactCard
 					{recipe}
-					{current_month}
 					routePrefix={resolve('/[recipeLang=recipeLang]', { recipeLang: data.recipeLang })}
 				/>
 				<div class="translation-badge {recipe.translationStatus || 'none'}">

src/routes/[recipeLang=recipeLang]/category/[category]/+page.svelte

@@ -9,7 +9,6 @@
     type RecipeItem = BriefRecipeType & { isFavorite: boolean };
 
     let { data } = $props<{ data: PageData }>();
-    let current_month = new Date().getMonth() + 1;
 
     import { m, type RecipesLang } from '$lib/js/recipesI18n';
     const lang = $derived(data.lang as RecipesLang);
@@ -47,6 +46,6 @@
 <Search category={data.category} lang={data.lang} recipes={data.allRecipes} isLoggedIn={!!data.session?.user} onSearchResults={handleSearchResults}></Search>
 <div class="recipe-grid">
 	{#each rand_array(displayRecipes) as recipe (recipe._id)}
-		<CompactCard {recipe} {current_month} isFavorite={recipe.isFavorite} showFavoriteIndicator={!!data.session?.user} routePrefix={resolve('/[recipeLang=recipeLang]', { recipeLang: data.recipeLang })} />
+		<CompactCard {recipe} isFavorite={recipe.isFavorite} showFavoriteIndicator={!!data.session?.user} routePrefix={resolve('/[recipeLang=recipeLang]', { recipeLang: data.recipeLang })} />
 	{/each}
 </div>

src/routes/[recipeLang=recipeLang]/edit/[name]/+page.svelte

@@ -12,7 +12,7 @@
 	import CreateIngredientList from '$lib/components/recipes/CreateIngredientList.svelte';
 	import CreateStepList from '$lib/components/recipes/CreateStepList.svelte';
 	import Toggle from '$lib/components/Toggle.svelte';
-	import { season } from '$lib/js/season_store';
+	import type { SeasonRange } from '$types/types';
 	import { portions } from '$lib/js/portions_store';
 	import '$lib/css/action_button.css';
 	import { toast } from '$lib/js/toast.svelte';
@@ -57,14 +57,7 @@
 	});
 
 	// svelte-ignore state_referenced_locally
-	season.update(() => data.recipe.season || []);
-	// svelte-ignore state_referenced_locally
-	let season_local = $state<number[]>(data.recipe.season || []);
-	$effect(() => {
-		season.subscribe((s) => {
-			season_local = s;
-		});
-	});
+	let season_local = $state<SeasonRange[]>(data.recipe.seasonRanges || []);
 
 	// svelte-ignore state_referenced_locally
 	let card_data = $state({
@@ -111,21 +104,6 @@
 	let submitting = $state(false);
 	let formElement: HTMLFormElement;
 
-	// Get season data from checkboxes
-	function get_season(): number[] {
-		const season: number[] = [];
-		const el = document.getElementById("labels");
-		if (!el) return season;
-
-		for (let i = 0; i < el.children.length; i++) {
-			const checkbox = el.children[i].children[0].children[0] as HTMLInputElement;
-			if (checkbox?.checked) {
-				season.push(i + 1);
-			}
-		}
-		return season;
-	}
-
 	// Get current German recipe data - use $derived to prevent infinite effect loops
 	let currentRecipeData = $derived.by(() => {
 		// Ensure we always have a valid images array with at least one item
@@ -153,7 +131,7 @@
 			...card_data,
 			...add_info,
 			images: recipeImages,
-			season: season_local,
+			seasonRanges: season_local,
 			short_name: short_name.trim(),
 			datecreated,
 			portions: portions_local,
@@ -1147,7 +1125,7 @@
 	<input type="hidden" name="ingredients_json" value={JSON.stringify(ingredients)} />
 	<input type="hidden" name="instructions_json" value={JSON.stringify(instructions)} />
 	<input type="hidden" name="add_info_json" value={JSON.stringify(add_info)} />
-	<input type="hidden" name="season" value={JSON.stringify(season_local)} />
+	<input type="hidden" name="seasonRanges" value={JSON.stringify(season_local)} />
 	<input type="hidden" name="tags" value={JSON.stringify(card_data.tags)} />
 	<input type="hidden" name="datecreated" value={datecreated?.toString()} />
 
@@ -1179,7 +1157,7 @@
 		{#snippet titleExtras()}
 			<h2 class="section-label">Saison</h2>
 			<div class="season-wrapper">
-				<SeasonSelect />
+				<SeasonSelect bind:ranges={season_local} />
 			</div>
 
 			<h2 class="section-label">Einleitung</h2>

src/routes/[recipeLang=recipeLang]/favorites/+page.svelte

@@ -5,7 +5,6 @@
     import Search from '$lib/components/recipes/Search.svelte';
 
     let { data } = $props<{ data: PageData }>();
-    let current_month = new Date().getMonth() + 1;
 
     import { m, type RecipesLang } from '$lib/js/recipesI18n';
     const lang = $derived(data.lang as RecipesLang);
@@ -100,7 +99,7 @@
 {:else if filteredFavorites.length > 0}
     <div class="recipe-grid">
         {#each filteredFavorites as recipe (recipe._id)}
-            <CompactCard {recipe} {current_month} isFavorite={true} showFavoriteIndicator={true} routePrefix={resolve('/[recipeLang=recipeLang]', { recipeLang: data.recipeLang })} />
+            <CompactCard {recipe} isFavorite={true} showFavoriteIndicator={true} routePrefix={resolve('/[recipeLang=recipeLang]', { recipeLang: data.recipeLang })} />
         {/each}
     </div>
 {:else if data.favorites.length > 0}

src/routes/[recipeLang=recipeLang]/search/+page.svelte

@@ -5,7 +5,6 @@
     import CompactCard from '$lib/components/recipes/CompactCard.svelte';
     import { m, type RecipesLang } from '$lib/js/recipesI18n';
     let { data } = $props<{ data: PageData }>();
-    let current_month = new Date().getMonth() + 1;
 
     const lang = $derived(data.lang as RecipesLang);
     const t = $derived(m[lang]);
@@ -111,7 +110,7 @@
 {#if displayedRecipes.length > 0}
     <div class="recipe-grid">
         {#each displayedRecipes as recipe (recipe._id)}
-            <CompactCard {recipe} {current_month} isFavorite={recipe.isFavorite} showFavoriteIndicator={true} routePrefix={resolve('/[recipeLang=recipeLang]', { recipeLang: data.recipeLang })} />
+            <CompactCard {recipe} isFavorite={recipe.isFavorite} showFavoriteIndicator={true} routePrefix={resolve('/[recipeLang=recipeLang]', { recipeLang: data.recipeLang })} />
         {/each}
     </div>
 {:else if (data.query || hasActiveSearch) && !data.error}

src/routes/[recipeLang=recipeLang]/season/+page.server.ts

@@ -4,8 +4,7 @@ import { getUserFavorites, addFavoriteStatusToRecipes } from "$lib/server/favori
 export const load: PageServerLoad = async ({ fetch, locals, params }) => {
     const apiBase = `/api/${params.recipeLang}`;
 
-    let current_month = new Date().getMonth() + 1
-    const res_season = await fetch(`${apiBase}/items/in_season/` + current_month);
+    const res_season = await fetch(`${apiBase}/items/in_season/today`);
     const item_season = await res_season.json();
 
     const session = locals.session ?? await locals.auth();

src/routes/[recipeLang=recipeLang]/season/+page.svelte

@@ -46,7 +46,7 @@
 	{#snippet recipesSlot()}
 		<div class="recipe-grid">
 			{#each rand_array(filteredRecipes) as recipe (recipe._id)}
-				<CompactCard {recipe} {current_month} isFavorite={recipe.isFavorite} showFavoriteIndicator={!!data.session?.user} routePrefix={resolve('/[recipeLang=recipeLang]', { recipeLang: data.recipeLang })} />
+				<CompactCard {recipe} icon_override={true} isFavorite={recipe.isFavorite} showFavoriteIndicator={!!data.session?.user} routePrefix={resolve('/[recipeLang=recipeLang]', { recipeLang: data.recipeLang })} />
 			{/each}
 		</div>
 	{/snippet}

src/routes/[recipeLang=recipeLang]/season/+page.ts

@@ -1,6 +1,6 @@
 import { browser } from '$app/environment';
 import { isOffline, canUseOfflineData } from '$lib/offline/helpers';
-import { getBriefRecipesBySeason, isOfflineDataAvailable } from '$lib/offline/db';
+import { getBriefRecipesInSeasonOn, isOfflineDataAvailable } from '$lib/offline/db';
 import { rand_array } from '$lib/js/randomize';
 import type { PageLoad } from './$types';
 
@@ -20,8 +20,7 @@ export const load: PageLoad = async ({ data }) => {
         try {
             const hasOfflineData = await isOfflineDataAvailable();
             if (hasOfflineData) {
-                const currentMonth = new Date().getMonth() + 1;
-                const recipes = await getBriefRecipesBySeason(currentMonth);
+                const recipes = await getBriefRecipesInSeasonOn(new Date());
 
                 return {
                     ...data,

src/routes/[recipeLang=recipeLang]/season/[month]/+page.ts

@@ -1,6 +1,6 @@
 import { browser } from '$app/environment';
 import { isOffline, canUseOfflineData } from '$lib/offline/helpers';
-import { getBriefRecipesBySeason, isOfflineDataAvailable } from '$lib/offline/db';
+import { getBriefRecipesOverlappingMonth, isOfflineDataAvailable } from '$lib/offline/db';
 import { rand_array } from '$lib/js/randomize';
 import type { PageLoad } from './$types';
 
@@ -21,7 +21,7 @@ export const load: PageLoad = async ({ data, params }) => {
 			const hasOfflineData = await isOfflineDataAvailable();
 			if (hasOfflineData) {
 				const month = parseInt(params.month);
-				const recipes = await getBriefRecipesBySeason(month);
+				const recipes = await getBriefRecipesOverlappingMonth(month);
 
 				return {
 					...data,

src/routes/[recipeLang=recipeLang]/tag/[tag]/+page.svelte

@@ -9,7 +9,6 @@
     type RecipeItem = BriefRecipeType & { isFavorite: boolean };
 
     let { data } = $props<{ data: PageData }>();
-    let current_month = new Date().getMonth() + 1;
 
     import { m, type RecipesLang } from '$lib/js/recipesI18n';
     const lang = $derived(data.lang as RecipesLang);
@@ -47,6 +46,6 @@
 <Search tag={data.tag} lang={data.lang} recipes={data.allRecipes} isLoggedIn={!!data.session?.user} onSearchResults={handleSearchResults}></Search>
 <div class="recipe-grid">
 	{#each rand_array(displayRecipes) as recipe (recipe._id)}
-		<CompactCard {recipe} {current_month} isFavorite={recipe.isFavorite} showFavoriteIndicator={!!data.session?.user} routePrefix={resolve('/[recipeLang=recipeLang]', { recipeLang: data.recipeLang })} />
+		<CompactCard {recipe} isFavorite={recipe.isFavorite} showFavoriteIndicator={!!data.session?.user} routePrefix={resolve('/[recipeLang=recipeLang]', { recipeLang: data.recipeLang })} />
 	{/each}
 </div>

src/routes/api/[recipeLang=recipeLang]/favorites/recipes/+server.ts

@@ -51,7 +51,7 @@ export const GET: RequestHandler = async ({ params, locals }) => {
         description: t?.description,
         note: t?.note,
         tags: t?.tags || [],
-        season: recipe.season,
+        seasonRanges: recipe.seasonRanges,
         baking: recipe.baking,
         preparation: recipe.preparation,
         fermentation: recipe.fermentation,

src/routes/api/[recipeLang=recipeLang]/items/[name]/+server.ts

@@ -142,7 +142,7 @@ export const GET: RequestHandler = async ({ params, setHeaders }) => {
       icon: rawRecipe.icon || '',
       dateCreated: rawRecipe.dateCreated,
       dateModified: rawRecipe.dateModified,
-      season: rawRecipe.season || [],
+      seasonRanges: rawRecipe.seasonRanges || [],
       baking: t.baking || rawRecipe.baking || { temperature: '', length: '', mode: '' },
       preparation: t.preparation || rawRecipe.preparation || '',
       fermentation: t.fermentation || rawRecipe.fermentation || { bulk: '', final: '' },

src/routes/api/[recipeLang=recipeLang]/items/in_season/[month]/+server.ts

@@ -3,18 +3,24 @@ import { Recipe } from '$models/Recipe';
 import { dbConnect } from '$utils/db';
 import { rand_array } from '$lib/js/randomize';
 import { briefQueryConfig, toBrief } from '$lib/server/recipeHelpers';
+import { recipeOverlapsMonth } from '$lib/js/seasonRange';
 
 export const GET: RequestHandler = async ({ params, setHeaders }) => {
   const { approvalFilter, projection } = briefQueryConfig(params.recipeLang!);
 
   await dbConnect();
+  const month = parseInt(params.month!, 10);
+
+  // Range membership for movable anchors can't be expressed in Mongo, so we
+  // load every approved (non-plate-icon) recipe with seasonRanges and filter
+  // in-app. Dataset is small (~hundreds) — sub-ms.
   const dbRecipes = await Recipe.find(
-    { season: parseInt(params.month!, 10), icon: { $ne: "🍽️" }, ...approvalFilter },
+    { icon: { $ne: '🍽️' }, seasonRanges: { $exists: true, $ne: [] }, ...approvalFilter },
     projection
   ).lean();
-  const recipes = dbRecipes.map(r => toBrief(r, params.recipeLang!));
+  const briefs = dbRecipes.map(r => toBrief(r, params.recipeLang!));
+  const recipes = briefs.filter(r => recipeOverlapsMonth(r as any, month));
 
-  // rand_array is seeded per UTC day, same for every caller → cacheable.
   setHeaders({ 'Cache-Control': 'public, max-age=28800, s-maxage=28800, stale-while-revalidate=86400' });
   return json(rand_array(recipes));
 };

src/routes/api/[recipeLang=recipeLang]/items/in_season/today/+server.ts

@@ -0,0 +1,27 @@
+import { json, type RequestHandler } from '@sveltejs/kit';
+import { Recipe } from '$models/Recipe';
+import { dbConnect } from '$utils/db';
+import { rand_array } from '$lib/js/randomize';
+import { briefQueryConfig, toBrief } from '$lib/server/recipeHelpers';
+import { isRecipeInSeason } from '$lib/js/seasonRange';
+
+export const GET: RequestHandler = async ({ params, setHeaders }) => {
+  const { approvalFilter, projection } = briefQueryConfig(params.recipeLang!);
+
+  await dbConnect();
+
+  // Same shape as the [month] endpoint: load all candidates, filter in-app
+  // against the resolved liturgical anchors for the current date.
+  const dbRecipes = await Recipe.find(
+    { icon: { $ne: '🍽️' }, seasonRanges: { $exists: true, $ne: [] }, ...approvalFilter },
+    projection
+  ).lean();
+  const briefs = dbRecipes.map(r => toBrief(r, params.recipeLang!));
+  const today = new Date();
+  const recipes = briefs.filter(r => isRecipeInSeason(r as any, today));
+
+  // 1h browser, 1h edge, 24h SWR — anchors are stable within a day, daily
+  // revalidation is fine for season transitions.
+  setHeaders({ 'Cache-Control': 'public, max-age=3600, s-maxage=3600, stale-while-revalidate=86400' });
+  return json(rand_array(recipes));
+};

src/routes/api/[recipeLang=recipeLang]/offline-db/+server.ts

@@ -10,7 +10,7 @@ export const GET: RequestHandler = async () => {
 	const [briefRecipes, fullRecipes] = await Promise.all([
 		Recipe.find(
 			{},
-			'name short_name tags category icon description season dateModified images translations'
+			'name short_name tags category icon description seasonRanges dateModified images translations'
 		).lean() as unknown as Promise<BriefRecipeType[]>,
 		Recipe.find({})
 		.populate({

src/routes/api/[recipeLang=recipeLang]/search/+server.ts

@@ -3,6 +3,7 @@ import type { BriefRecipeType } from '$types/types';
 import { Recipe } from '$models/Recipe';
 import { dbConnect } from '$utils/db';
 import { isEnglish, briefQueryConfig, toBrief } from '$lib/server/recipeHelpers';
+import { recipeOverlapsMonth } from '$lib/js/seasonRange';
 
 export const GET: RequestHandler = async ({ url, params, locals }) => {
   await dbConnect();
@@ -41,13 +42,18 @@ export const GET: RequestHandler = async ({ url, params, locals }) => {
     if (icon) {
       dbQuery.icon = icon;
     }
-    if (seasons.length > 0) {
-      dbQuery.season = { $in: seasons };
-    }
 
     const dbRecipes = await Recipe.find(dbQuery, projection).lean();
     let recipes: BriefRecipeType[] = dbRecipes.map(r => toBrief(r, params.recipeLang!));
 
+    // Season filter: ranges with movable anchors can't be expressed in Mongo,
+    // so filter in-app. Range-based recipes resolve to concrete intervals via
+    // the shared evaluator; the recipe matches if any selected month overlaps
+    // any of its ranges in the current civil year (with year-wrap handling).
+    if (seasons.length > 0) {
+      recipes = recipes.filter(r => seasons.some(m => recipeOverlapsMonth(r as any, m)));
+    }
+
     // Handle favorites filter
     const session = locals.session ?? await locals.auth();
     if (favoritesOnly && session?.user) {

src/routes/api/[recipeLang=recipeLang]/translate/untranslated/+server.ts

@@ -22,7 +22,7 @@ export const GET: RequestHandler = async ({ locals }) => {
 				{ 'translations.en': { $exists: false } },
 				{ 'translations.en.translationStatus': { $ne: 'approved' } }
 			]
-		}, 'name short_name category icon description tags season dateModified translations.en.translationStatus')
+		}, 'name short_name category icon description tags seasonRanges dateModified translations.en.translationStatus')
 		.sort({ dateModified: 1 }) // Oldest first - highest priority
 		.lean();
 
@@ -35,7 +35,7 @@ export const GET: RequestHandler = async ({ locals }) => {
 			icon: recipe.icon,
 			description: recipe.description,
 			tags: recipe.tags || [],
-			season: recipe.season || [],
+			seasonRanges: recipe.seasonRanges || [],
 			dateModified: recipe.dateModified,
 			translationStatus: recipe.translations?.en?.translationStatus || undefined
 		}));

src/types/types.ts

@@ -37,6 +37,24 @@ export type NutritionMapping = {
   recipeRefMultiplier?: number;
 };
 
+// Movable liturgical anchors usable as range endpoints. Fixed feasts
+// (Christmas, Epiphany, etc.) are expressed as `{kind:'fixed', m, d}`.
+export type SeasonAnchorKey =
+  | 'easter'
+  | 'ash-wednesday'
+  | 'palm-sunday'
+  | 'pentecost'
+  | 'advent-i';
+
+export type SeasonEndpoint =
+  | { kind: 'fixed'; m: number; d: number }
+  | { kind: 'liturgical'; anchor: SeasonAnchorKey; offsetDays: number };
+
+export type SeasonRange = {
+  start: SeasonEndpoint;
+  end: SeasonEndpoint;
+};
+
 // Translation status enum
 export type TranslationStatus = 'pending' | 'approved' | 'needs_update';
 
@@ -175,7 +193,7 @@ export type RecipeModelType = {
   }];
   description: string;
   tags: [string];
-  season: [number];
+  seasonRanges?: SeasonRange[];
   baking?: {
 	  temperature: string;
 	  length: string;
@@ -225,5 +243,5 @@ export type BriefRecipeType = {
 	}]
 	description: string;
 	tags: [string];
-	season: [number];
+	seasonRanges?: SeasonRange[];
 }

src/utils/recipeFormHelpers.ts

@@ -5,7 +5,7 @@
  * for SvelteKit form actions with progressive enhancement support.
  */
 
-import type { IngredientItem, InstructionItem, TranslatedRecipeType, TranslationMetadata } from '$types/types';
+import type { IngredientItem, InstructionItem, SeasonRange, TranslatedRecipeType, TranslationMetadata } from '$types/types';
 
 export interface RecipeFormData {
 	// Basic fields
@@ -16,7 +16,7 @@ export interface RecipeFormData {
 	icon: string;
 	tags: string[];
 	portions: string;
-	season: number[];
+	seasonRanges: SeasonRange[];
 
 	// Optional text fields
 	preamble?: string;
@@ -97,14 +97,14 @@ export function extractRecipeFromFormData(formData: FormData): RecipeFormData {
 		}
 	}
 
-	// Season (JSON array of month numbers)
-	let season: number[] = [];
-	const seasonData = formData.get('season')?.toString();
-	if (seasonData) {
+	// Season ranges (JSON array of {start, end} endpoints)
+	let seasonRanges: SeasonRange[] = [];
+	const seasonRangesData = formData.get('seasonRanges')?.toString();
+	if (seasonRangesData) {
 		try {
-			season = JSON.parse(seasonData);
+			seasonRanges = JSON.parse(seasonRangesData);
 		} catch {
-			// Ignore invalid season data
+			// Ignore invalid range data
 		}
 	}
 
@@ -207,7 +207,7 @@ export function extractRecipeFromFormData(formData: FormData): RecipeFormData {
 		icon,
 		tags,
 		portions,
-		season,
+		seasonRanges,
 		preamble,
 		addendum,
 		note,
@@ -294,8 +294,8 @@ export function detectChangedFields(original: Record<string, unknown>, current:
 		changedFields.push('tags');
 	}
 
-	if (JSON.stringify(original.season) !== JSON.stringify(current.season)) {
-		changedFields.push('season');
+	if (JSON.stringify(original.seasonRanges) !== JSON.stringify(current.seasonRanges)) {
+		changedFields.push('seasonRanges');
 	}
 
 	if (JSON.stringify(original.ingredients) !== JSON.stringify(current.ingredients)) {
@@ -319,32 +319,18 @@ export function detectChangedFields(original: Record<string, unknown>, current:
 }
 
 /**
- * Parses season data from form input
- * Handles both checkbox-based input and JSON arrays
+ * Parses season-range data from form input (JSON-encoded SeasonRange[]).
  */
-export function parseSeasonData(formData: FormData): number[] {
-	const season: number[] = [];
-
-	// Try JSON format first
-	const seasonJson = formData.get('season')?.toString();
-	if (seasonJson) {
+export function parseSeasonRangesData(formData: FormData): SeasonRange[] {
+	const seasonJson = formData.get('seasonRanges')?.toString();
+	if (!seasonJson) return [];
 	try {
 		return JSON.parse(seasonJson);
 	} catch {
-			// Fall through to checkbox parsing
+		return [];
 	}
 }
 
-	// Parse individual checkbox inputs (season_1, season_2, etc.)
-	for (let month = 1; month <= 12; month++) {
-		if (formData.get(`season_${month}`) === 'true') {
-			season.push(month);
-		}
-	}
-
-	return season;
-}
-
 /**
  * Serializes complex recipe data for storage
  * Ensures all required fields are present and properly typed
@@ -358,7 +344,7 @@ export function serializeRecipeForDatabase(data: RecipeFormData): Record<string,
 		icon: data.icon || '',
 		tags: data.tags || [],
 		portions: data.portions || '',
-		season: data.season || [],
+		seasonRanges: data.seasonRanges || [],
 		ingredients: data.ingredients || [],
 		instructions: data.instructions || [],
 		isBaseRecipe: data.isBaseRecipe || false,