diff --git a/CHANGELOG.md b/CHANGELOG.md
index 88d6cd2..2ced471 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.20.35] - 2026-04-20
+
+### Changed
+- Extracted ICS parser functions (`unfoldLines`, `parseICS`, `formatICSDate`, `tzLocalToUTC`, `applyDuration`) from `apple-calendar.js` into a new shared module `server/services/ics-parser.js`, plus a new `expandRRULE` helper — pure refactor, no logic changes
+- Added `test:ics-parser` test suite covering line unfolding, all-day/UTC event parsing, and RRULE expansion
+
 ## [0.20.34] - 2026-04-20
 
 ### Fixed
diff --git a/package.json b/package.json
index 5a1aaa3..7f67458 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "oikos",
-  "version": "0.20.34",
+  "version": "0.20.35",
   "description": "Self-hosted family planner - calendar, tasks, shopping, meal planning, budget and more. Private, open-source, no subscription.",
   "main": "server/index.js",
   "type": "module",
@@ -22,7 +22,8 @@
     "test:modal-utils": "node --loader ./test-browser-loader.mjs test-modal-utils.js",
     "test:reminders": "node --experimental-sqlite test-reminders.js",
     "test:api": "node test-api.js",
-    "test": "node --experimental-sqlite test-db.js && node --experimental-sqlite test-dashboard.js && node --experimental-sqlite test-tasks.js && node --experimental-sqlite test-shopping.js && node --experimental-sqlite test-meals.js && node --experimental-sqlite test-calendar.js && node --experimental-sqlite test-notes-contacts-budget.js && npm run test:ux-utils && npm run test:modal-utils && npm run test:reminders && npm run test:api"
+    "test:ics-parser": "node test-ics-parser.js",
+    "test": "node --experimental-sqlite test-db.js && node --experimental-sqlite test-dashboard.js && node --experimental-sqlite test-tasks.js && node --experimental-sqlite test-shopping.js && node --experimental-sqlite test-meals.js && node --experimental-sqlite test-calendar.js && node --experimental-sqlite test-notes-contacts-budget.js && npm run test:ux-utils && npm run test:modal-utils && npm run test:reminders && npm run test:api && node test-ics-parser.js"
   },
   "dependencies": {
     "bcrypt": "^6.0.0",
diff --git a/server/services/apple-calendar.js b/server/services/apple-calendar.js
index 94bbf62..a21c66a 100644
--- a/server/services/apple-calendar.js
+++ b/server/services/apple-calendar.js
@@ -16,6 +16,7 @@ import { createLogger } from '../logger.js';
 const log = createLogger('Apple');
 
 import * as db from '../db.js';
+import { unfoldLines, parseICS, formatICSDate, tzLocalToUTC, applyDuration } from './ics-parser.js';
 
 const APPLE_COLOR = '#FC3C44';
 
@@ -101,191 +102,6 @@ async function testConnection() {
   return { ok: true, calendarCount: calendars.length };
 }
 
-// --------------------------------------------------------
-// Minimaler ICS-Parser
-// --------------------------------------------------------
-
-/**
- * Entfaltet ICS-Zeilenfortsetzungen (RFC 5545 §3.1).
- * @param {string} ics
- * @returns {string}
- */
-function unfoldLines(ics) {
-  return ics.replace(/\r?\n[ \t]/g, '');
-}
-
-/**
- * Extrahiert alle VEVENT-Blöcke aus einem ICS-String.
- * @param {string} ics
- * @returns {Array<{uid, summary, description, location, dtstart, dtend, rrule, allDay}>}
- */
-function parseICS(ics) {
-  const unfolded = unfoldLines(ics);
-  const events   = [];
-  const vEventRe = /BEGIN:VEVENT([\s\S]*?)END:VEVENT/g;
-  let match;
-
-  while ((match = vEventRe.exec(unfolded)) !== null) {
-    const block = match[1];
-    const get   = (prop) => {
-      const re = new RegExp(`^${prop}(?:;[^:]*)?:(.*)$`, 'im');
-      const m  = re.exec(block);
-      return m ? m[1].trim() : null;
-    };
-
-    const uid         = get('UID');
-    const summary     = get('SUMMARY') || '(kein Titel)';
-    const description = get('DESCRIPTION') || null;
-    const location    = get('LOCATION')    || null;
-    const rrule       = get('RRULE')       ? `RRULE:${get('RRULE')}` : null;
-
-    // DTSTART / DTEND - extract value and optional TZID parameter
-    const parseDTLine = (prop) => {
-      const re = new RegExp(`^${prop}((?:;[^:]*)*):(.*)$`, 'im');
-      const m = block.match(re);
-      if (!m) return { value: null, tzid: null };
-      const params  = m[1];
-      const value   = m[2].trim();
-      const tzMatch = params.match(/;TZID=([^;:]+)/i);
-      return { value, tzid: tzMatch ? tzMatch[1].trim() : null };
-    };
-
-    const dtStartLine = parseDTLine('DTSTART');
-    const dtEndLine   = parseDTLine('DTEND');
-    const dtStartRaw  = dtStartLine.value;
-    const dtEndRaw    = dtEndLine.value;
-
-    const allDay  = /^DTSTART;VALUE=DATE:/im.test(block);
-    const dtstart = dtStartRaw ? formatICSDate(dtStartRaw, allDay, dtStartLine.tzid) : null;
-    let   dtend   = dtEndRaw   ? formatICSDate(dtEndRaw,   allDay, dtEndLine.tzid)   : null;
-
-    // RFC 5545: DTEND for VALUE=DATE is exclusive - subtract one day
-    if (allDay && dtend) {
-      const d = new Date(dtend + 'T00:00:00');
-      d.setDate(d.getDate() - 1);
-      dtend = `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, '0')}-${String(d.getDate()).padStart(2, '0')}`;
-    }
-
-    // DURATION fallback when DTEND is missing (e.g. DURATION:P3D)
-    if (!dtend && dtstart) {
-      const durMatch = /^DURATION(?:;[^:]*)?:(.*)$/im.exec(block);
-      if (durMatch) {
-        dtend = applyDuration(dtstart, durMatch[1].trim(), allDay);
-      }
-    }
-
-    if (!uid || !dtstart) continue;
-
-    events.push({ uid, summary, description, location, dtstart, dtend, rrule, allDay });
-  }
-
-  return events;
-}
-
-/**
- * Converts a local datetime string in a named timezone to UTC ISO-8601.
- * Uses the Intl API (Node.js 12+) without external dependencies.
- * @param {string} localStr - "YYYY-MM-DDTHH:MM:SS"
- * @param {string} tzid - IANA timezone name e.g. "Europe/Helsinki"
- * @returns {string} UTC ISO string ending with 'Z', or localStr on error
- */
-function tzLocalToUTC(localStr, tzid) {
-  try {
-    // Treat the local time as if it were UTC to create a reference point
-    const fakeUTC = new Date(localStr + 'Z');
-
-    // Find out what fakeUTC looks like in the target timezone
-    const parts = new Intl.DateTimeFormat('en-US', {
-      timeZone: tzid,
-      year: 'numeric', month: 'numeric', day: 'numeric',
-      hour: 'numeric', minute: 'numeric', second: 'numeric',
-      hour12: false,
-    }).formatToParts(fakeUTC);
-
-    const get = (type) => {
-      const part = parts.find(p => p.type === type);
-      const v = part ? part.value : '0';
-      return v === '24' ? 0 : parseInt(v, 10);
-    };
-
-    // Compute offset: how much the timezone differs from what we fed in
-    const tzDisplayedAsUTC = Date.UTC(
-      get('year'), get('month') - 1, get('day'),
-      get('hour'), get('minute'), get('second')
-    );
-    const offsetMs = fakeUTC.getTime() - tzDisplayedAsUTC;
-
-    const trueUTC = new Date(fakeUTC.getTime() + offsetMs);
-    return trueUTC.toISOString().replace('.000Z', 'Z');
-  } catch {
-    return localStr;
-  }
-}
-
-/**
- * Konvertiert ICS-Datumswert in ISO-8601-String.
- * Unterstützt: DATE (20240101), DATE-TIME lokal (20240101T120000),
- *              DATE-TIME UTC (20240101T120000Z), DATE-TIME mit TZID (konvertiert zu UTC).
- * @param {string} val
- * @param {boolean} allDay
- * @param {string|null} tzid - IANA timezone from TZID parameter, if present
- * @returns {string}
- */
-function formatICSDate(val, allDay, tzid) {
-  if (allDay || /^\d{8}$/.test(val)) {
-    // DATE: YYYYMMDD → YYYY-MM-DD
-    return `${val.slice(0, 4)}-${val.slice(4, 6)}-${val.slice(6, 8)}`;
-  }
-  // DATE-TIME: YYYYMMDDTHHMMSS[Z]
-  const y  = val.slice(0, 4);
-  const mo = val.slice(4, 6);
-  const d  = val.slice(6, 8);
-  const h  = val.slice(9, 11);
-  const mi = val.slice(11, 13);
-  const s  = val.slice(13, 15) || '00';
-
-  if (val.endsWith('Z')) {
-    // Already UTC
-    return `${y}-${mo}-${d}T${h}:${mi}:${s}Z`;
-  }
-
-  if (tzid) {
-    // Convert from named timezone to UTC
-    return tzLocalToUTC(`${y}-${mo}-${d}T${h}:${mi}:${s}`, tzid);
-  }
-
-  // Floating local time - store without timezone suffix
-  return `${y}-${mo}-${d}T${h}:${mi}:${s}`;
-}
-
-/**
- * Berechnet ein Enddatum aus Start + ICS-DURATION (P-Format, Subset: PnW, PnD, PnDTnHnMnS).
- * Für all-day Events gibt es YYYY-MM-DD zurück (inklusive, bereits um 1 Tag reduziert),
- * für timed Events einen ISO-DateTime-String.
- */
-function applyDuration(dtstart, dur, allDay) {
-  const m = /^P(?:(\d+)W)?(?:(\d+)D)?(?:T(?:(\d+)H)?(?:(\d+)M)?(?:(\d+)S)?)?$/.exec(dur);
-  if (!m) return null;
-
-  const weeks = parseInt(m[1] || '0', 10);
-  const days  = parseInt(m[2] || '0', 10);
-  const hours = parseInt(m[3] || '0', 10);
-  const mins  = parseInt(m[4] || '0', 10);
-  const secs  = parseInt(m[5] || '0', 10);
-
-  const base = new Date(dtstart.includes('T') ? dtstart : dtstart + 'T00:00:00');
-  base.setDate(base.getDate() + weeks * 7 + days);
-  base.setHours(base.getHours() + hours, base.getMinutes() + mins, base.getSeconds() + secs);
-
-  if (allDay) {
-    // Duration end is exclusive for DATE values - subtract one day for inclusive storage
-    base.setDate(base.getDate() - 1);
-    return `${base.getFullYear()}-${String(base.getMonth() + 1).padStart(2, '0')}-${String(base.getDate()).padStart(2, '0')}`;
-  }
-
-  return base.toISOString().replace('.000Z', 'Z');
-}
-
 // --------------------------------------------------------
 // Minimaler ICS-Builder
 // --------------------------------------------------------
diff --git a/server/services/ics-parser.js b/server/services/ics-parser.js
new file mode 100644
index 0000000..c87d065
--- /dev/null
+++ b/server/services/ics-parser.js
@@ -0,0 +1,143 @@
+import { nextOccurrence } from './recurrence.js';
+
+function unfoldLines(ics) {
+  return ics.replace(/\r?\n[ \t]/g, '');
+}
+
+function parseICS(ics) {
+  const unfolded = unfoldLines(ics);
+  const events   = [];
+  const vEventRe = /BEGIN:VEVENT([\s\S]*?)END:VEVENT/g;
+  let match;
+  while ((match = vEventRe.exec(unfolded)) !== null) {
+    const block = match[1];
+    const get   = (prop) => {
+      const re = new RegExp(`^${prop}(?:;[^:]*)?:(.*)$`, 'im');
+      const m  = re.exec(block);
+      return m ? m[1].trim() : null;
+    };
+    const uid         = get('UID');
+    const summary     = get('SUMMARY') || '(kein Titel)';
+    const description = get('DESCRIPTION') || null;
+    const location    = get('LOCATION')    || null;
+    const rrule       = get('RRULE')       ? `RRULE:${get('RRULE')}` : null;
+    const parseDTLine = (prop) => {
+      const re = new RegExp(`^${prop}((?:;[^:]*)*):(.*)$`, 'im');
+      const m = block.match(re);
+      if (!m) return { value: null, tzid: null };
+      const params  = m[1];
+      const value   = m[2].trim();
+      const tzMatch = params.match(/;TZID=([^;:]+)/i);
+      return { value, tzid: tzMatch ? tzMatch[1].trim() : null };
+    };
+    const dtStartLine = parseDTLine('DTSTART');
+    const dtEndLine   = parseDTLine('DTEND');
+    const dtStartRaw  = dtStartLine.value;
+    const dtEndRaw    = dtEndLine.value;
+    const allDay  = /^DTSTART;VALUE=DATE:/im.test(block);
+    const dtstart = dtStartRaw ? formatICSDate(dtStartRaw, allDay, dtStartLine.tzid) : null;
+    let   dtend   = dtEndRaw   ? formatICSDate(dtEndRaw,   allDay, dtEndLine.tzid)   : null;
+    if (allDay && dtend) {
+      const d = new Date(dtend + 'T00:00:00');
+      d.setDate(d.getDate() - 1);
+      dtend = `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, '0')}-${String(d.getDate()).padStart(2, '0')}`;
+    }
+    if (!dtend && dtstart) {
+      const durMatch = /^DURATION(?:;[^:]*)?:(.*)$/im.exec(block);
+      if (durMatch) dtend = applyDuration(dtstart, durMatch[1].trim(), allDay);
+    }
+    if (!uid || !dtstart) continue;
+    events.push({ uid, summary, description, location, dtstart, dtend, rrule, allDay });
+  }
+  return events;
+}
+
+function tzLocalToUTC(localStr, tzid) {
+  try {
+    const fakeUTC = new Date(localStr + 'Z');
+    const parts = new Intl.DateTimeFormat('en-US', {
+      timeZone: tzid, year: 'numeric', month: 'numeric', day: 'numeric',
+      hour: 'numeric', minute: 'numeric', second: 'numeric', hour12: false,
+    }).formatToParts(fakeUTC);
+    const get = (type) => {
+      const part = parts.find(p => p.type === type);
+      const v = part ? part.value : '0';
+      return v === '24' ? 0 : parseInt(v, 10);
+    };
+    const tzDisplayedAsUTC = Date.UTC(
+      get('year'), get('month') - 1, get('day'), get('hour'), get('minute'), get('second')
+    );
+    const offsetMs = fakeUTC.getTime() - tzDisplayedAsUTC;
+    return new Date(fakeUTC.getTime() + offsetMs).toISOString().replace('.000Z', 'Z');
+  } catch { return localStr; }
+}
+
+function formatICSDate(val, allDay, tzid) {
+  if (allDay || /^\d{8}$/.test(val)) {
+    return `${val.slice(0, 4)}-${val.slice(4, 6)}-${val.slice(6, 8)}`;
+  }
+  const y = val.slice(0, 4), mo = val.slice(4, 6), d = val.slice(6, 8);
+  const h = val.slice(9, 11), mi = val.slice(11, 13), s = val.slice(13, 15) || '00';
+  if (val.endsWith('Z')) return `${y}-${mo}-${d}T${h}:${mi}:${s}Z`;
+  if (tzid) return tzLocalToUTC(`${y}-${mo}-${d}T${h}:${mi}:${s}`, tzid);
+  return `${y}-${mo}-${d}T${h}:${mi}:${s}`;
+}
+
+function applyDuration(dtstart, dur, allDay) {
+  const m = /^P(?:(\d+)W)?(?:(\d+)D)?(?:T(?:(\d+)H)?(?:(\d+)M)?(?:(\d+)S)?)?$/.exec(dur);
+  if (!m) return null;
+  const weeks = parseInt(m[1] || '0', 10), days  = parseInt(m[2] || '0', 10);
+  const hours = parseInt(m[3] || '0', 10), mins  = parseInt(m[4] || '0', 10);
+  const secs  = parseInt(m[5] || '0', 10);
+  const base = new Date(dtstart.includes('T') ? dtstart : dtstart + 'T00:00:00');
+  base.setDate(base.getDate() + weeks * 7 + days);
+  base.setHours(base.getHours() + hours, base.getMinutes() + mins, base.getSeconds() + secs);
+  if (allDay) {
+    base.setDate(base.getDate() - 1);
+    return `${base.getFullYear()}-${String(base.getMonth() + 1).padStart(2, '0')}-${String(base.getDate()).padStart(2, '0')}`;
+  }
+  return base.toISOString().replace('.000Z', 'Z');
+}
+
+function expandRRULE(vevent, windowStart, windowEnd) {
+  if (!vevent.rrule) return [];
+  const results    = [];
+  const startDate  = vevent.dtstart.slice(0, 10);
+  const timeSuffix = vevent.allDay ? '' : (vevent.dtstart.slice(10) || '');
+  let durationMs = null;
+  if (vevent.dtend) {
+    const s = new Date(vevent.allDay ? vevent.dtstart + 'T00:00:00Z' : vevent.dtstart);
+    const e = new Date(vevent.allDay ? vevent.dtend   + 'T00:00:00Z' : vevent.dtend);
+    if (!isNaN(s) && !isNaN(e)) durationMs = e - s;
+  }
+  let current = startDate, iterations = 0;
+  const MAX_ITER = 1500;
+  while (current <= windowEnd && iterations < MAX_ITER) {
+    iterations++;
+    if (current >= windowStart) {
+      const occStart = current + timeSuffix;
+      let occEnd = null;
+      if (durationMs !== null) {
+        if (vevent.allDay) {
+          const d = new Date(current + 'T00:00:00Z');
+          d.setUTCMilliseconds(d.getUTCMilliseconds() + durationMs);
+          occEnd = d.toISOString().slice(0, 10);
+        } else {
+          occEnd = new Date(new Date(occStart).getTime() + durationMs)
+            .toISOString().replace('.000Z', 'Z');
+        }
+      }
+      results.push({
+        uid: `${vevent.uid}__${current}`, summary: vevent.summary,
+        description: vevent.description, location: vevent.location,
+        dtstart: occStart, dtend: occEnd, rrule: null, allDay: vevent.allDay,
+      });
+    }
+    const next = nextOccurrence(current, vevent.rrule);
+    if (!next || next <= current) break;
+    current = next;
+  }
+  return results;
+}
+
+export { unfoldLines, parseICS, formatICSDate, tzLocalToUTC, applyDuration, expandRRULE };
diff --git a/test-ics-parser.js b/test-ics-parser.js
new file mode 100644
index 0000000..f1db3fc
--- /dev/null
+++ b/test-ics-parser.js
@@ -0,0 +1,57 @@
+import { unfoldLines, parseICS, expandRRULE } from './server/services/ics-parser.js';
+
+let passed = 0, failed = 0;
+function test(name, fn) {
+  try { fn(); console.log(`  ✓ ${name}`); passed++; }
+  catch (err) { console.error(`  ✗ ${name}: ${err.message}`); failed++; }
+}
+function assert(cond, msg) { if (!cond) throw new Error(msg || 'Assertion failed'); }
+
+console.log('\n[ICS-Parser-Test]\n');
+
+test('unfoldLines entfaltet Zeilenfortsetzungen', () => {
+  const result = unfoldLines('SUMMARY:Hallo\r\n Welt');
+  assert(result === 'SUMMARY:HalloWelt', `got: ${result}`);
+});
+
+test('parseICS: einfaches Ganztags-Event', () => {
+  const ics = 'BEGIN:VCALENDAR\r\nBEGIN:VEVENT\r\nUID:test-1@x\r\nSUMMARY:Geburtstag\r\nDTSTART;VALUE=DATE:20260501\r\nDTEND;VALUE=DATE:20260502\r\nEND:VEVENT\r\nEND:VCALENDAR';
+  const events = parseICS(ics);
+  assert(events.length === 1, `expected 1, got ${events.length}`);
+  assert(events[0].uid === 'test-1@x', 'uid');
+  assert(events[0].dtstart === '2026-05-01', `dtstart: ${events[0].dtstart}`);
+  assert(events[0].dtend   === '2026-05-01', `dtend: ${events[0].dtend}`);
+  assert(events[0].allDay  === true, 'allDay');
+});
+
+test('parseICS: Event ohne UID wird übersprungen', () => {
+  const ics = 'BEGIN:VCALENDAR\r\nBEGIN:VEVENT\r\nSUMMARY:Ohne UID\r\nDTSTART:20260601T100000Z\r\nEND:VEVENT\r\nEND:VCALENDAR';
+  assert(parseICS(ics).length === 0, 'should skip event without UID');
+});
+
+test('parseICS: UTC datetime', () => {
+  const ics = 'BEGIN:VCALENDAR\r\nBEGIN:VEVENT\r\nUID:utc@x\r\nSUMMARY:Meeting\r\nDTSTART:20260615T140000Z\r\nDTEND:20260615T150000Z\r\nEND:VEVENT\r\nEND:VCALENDAR';
+  const [ev] = parseICS(ics);
+  assert(ev.dtstart === '2026-06-15T14:00:00Z', `dtstart: ${ev.dtstart}`);
+  assert(ev.allDay  === false, 'allDay');
+});
+
+test('expandRRULE: WEEKLY 3-Wochen-Fenster', () => {
+  const vevent = {
+    uid: 'weekly@x', summary: 'Wöchentlich', description: null, location: null,
+    dtstart: '2026-04-13', dtend: '2026-04-13', rrule: 'RRULE:FREQ=WEEKLY;BYDAY=MO', allDay: true,
+  };
+  const occ = expandRRULE(vevent, '2026-04-13', '2026-05-04');
+  assert(occ.length >= 3, `expected >=3, got ${occ.length}`);
+  assert(occ[0].uid === 'weekly@x__2026-04-13', `uid: ${occ[0].uid}`);
+  assert(occ[0].rrule === null, 'expanded events have null rrule');
+});
+
+test('expandRRULE: null rrule → leeres Array', () => {
+  const v = { uid: 'x', summary: 'x', description: null, location: null,
+              dtstart: '2026-04-20', dtend: null, rrule: null, allDay: true };
+  assert(expandRRULE(v, '2026-01-01', '2026-12-31').length === 0);
+});
+
+console.log(`\n${passed} passed, ${failed} failed`);
+if (failed > 0) process.exit(1);