diff --git a/server/services/appwriteAdmin.js b/server/services/appwriteAdmin.js
index b116c85..7b9805d 100644
--- a/server/services/appwriteAdmin.js
+++ b/server/services/appwriteAdmin.js
@@ -25,7 +25,8 @@ function formatRequestBody(body, method, { raw = false } = {}) {
   return payload
 }
 
-async function adminFetch(path, { method = 'GET', body, queries = [] } = {}) {
+/** raw: true schickt den Body unverpackt (sonst wird er zu { data, documentId }; Pfade unter /users sind immer roh). */
+async function adminFetch(path, { method = 'GET', body, queries = [], raw = false } = {}) {
   if (!config.appwrite.apiKey) {
     const error = new Error('APPWRITE_API_KEY fehlt in .env')
     error.status = 500
@@ -37,7 +38,7 @@ async function adminFetch(path, { method = 'GET', body, queries = [] } = {}) {
     url.searchParams.append('queries[]', q)
   }
 
-  const useRawBody = path.startsWith('/users')
+  const useRawBody = raw || path.startsWith('/users')
   const requestBody = formatRequestBody(body, method, { raw: useRawBody })
 
   const response = await fetch(url.toString(), {
@@ -77,6 +78,12 @@ export const Query = {
   limit: (n) => ({ method: 'limit', values: [n] }),
   greaterThan: (attribute, value) => ({ method: 'greaterThan', attribute, values: [value] }),
   lessThan: (attribute, value) => ({ method: 'lessThan', attribute, values: [value] }),
+  greaterThanEqual: (attribute, value) => ({ method: 'greaterThanEqual', attribute, values: [value] }),
+  lessThanEqual: (attribute, value) => ({ method: 'lessThanEqual', attribute, values: [value] }),
+  /** Beide Grenzen inklusiv */
+  between: (attribute, start, end) => ({ method: 'between', attribute, values: [start, end] }),
+  /** Seite nach dem Dokument mit dieser ID (zusammen mit orderAsc/orderDesc und limit) */
+  cursorAfter: (documentId) => ({ method: 'cursorAfter', values: [documentId] }),
   orderDesc: (attribute) => ({ method: 'orderDesc', attribute }),
   orderAsc: (attribute) => ({ method: 'orderAsc', attribute }),
 }
@@ -157,6 +164,34 @@ export async function listDocuments(collectionId, queries = []) {
   return result.documents
 }
 
+/**
+ * Ein Aufruf mit allen Seiten: sortiert nach $id, Seite fuer Seite per cursorAfter, bis eine Seite kuerzer als
+ * pageSize ist. queries enthalten nur Filter, nie limit/order/cursor (die setzt die Funktion selbst). Mehr als max
+ * Treffer ist ein Fehler (Schutz vor unbeabsichtigtem Vollabzug).
+ */
+export async function listAllDocuments(collectionId, queries = [], { pageSize = 500, max = 20000 } = {}) {
+  if (!Number.isInteger(pageSize) || pageSize < 1) throw new Error(`listAllDocuments: pageSize muss eine ganze Zahl ab 1 sein, nicht ${pageSize}`)
+  const all = []
+  let cursor = null
+  for (;;) {
+    const page = await listDocuments(collectionId, [
+      ...queries,
+      Query.limit(pageSize),
+      Query.orderAsc('$id'),
+      ...(cursor ? [Query.cursorAfter(cursor)] : []),
+    ])
+    all.push(...page)
+    if (all.length > max) {
+      const error = new Error(`listAllDocuments: mehr als ${max} Dokumente in ${collectionId}`)
+      error.status = 500
+      error.type = 'list_limit_exceeded'
+      throw error
+    }
+    if (page.length < pageSize) return all
+    cursor = page[page.length - 1].$id
+  }
+}
+
 export async function getCustomerByAppwriteUserId(appwriteUserId) {
   const docs = await listDocuments(config.collections.customers, [
     Query.equal('appwriteUserId', appwriteUserId),
@@ -218,6 +253,17 @@ export async function createDocument(collectionId, data, documentId = ID.unique(
   })
 }
 
+/**
+ * Mehrere Dokumente in einer Anfrage (Appwrite 1.8.1 Bulk-Create, hoechstens 100): alles oder nichts. Ist eine
+ * $id schon vergeben, antwortet Appwrite 409 document_already_exists und schreibt nichts (err.status === 409).
+ * Jedes Dokument bringt seine $id mit: [{ $id, ...felder }]. Liefert die angelegten Dokumente.
+ */
+export async function createDocuments(collectionId, documents) {
+  if (documents.length === 0) return []
+  const result = await adminFetch(collectionPath(collectionId), { method: 'POST', body: { documents }, raw: true })
+  return result.documents
+}
+
 export async function deleteDocument(collectionId, documentId) {
   return adminFetch(`${collectionPath(collectionId)}/${documentId}`, {
     method: 'DELETE',
diff --git a/test/appwriteBulk.test.js b/test/appwriteBulk.test.js
new file mode 100644
index 0000000..5667a80
--- /dev/null
+++ b/test/appwriteBulk.test.js
@@ -0,0 +1,226 @@
+import { test, after } from 'node:test'
+import assert from 'node:assert/strict'
+import express from 'express'
+import { startAppwriteMock } from './support/appwriteMock.js'
+import { startFakeStripe } from './support/fakeStripe.js'
+import { schemaKeys } from './support/schema.js'
+import { useTestEnv } from './support/testEnv.js'
+import { TERMINE_DATETIMES } from '../server/services/termine/schema.js'
+
+// Nachbau wie in den Termine-Tests (Schema, Datumsfelder, Standard-Limit 25) und einer ohne Optionen
+const aw = await startAppwriteMock({
+  schema: { termineClaims: schemaKeys('termineClaims'), termineBookings: schemaKeys('termineBookings'), termineOutbox: schemaKeys('termineOutbox') },
+  datetimes: TERMINE_DATETIMES,
+  defaultLimit: 25,
+})
+const plain = await startAppwriteMock()
+const st = await startFakeStripe()
+after(() => Promise.all([aw.close(), plain.close(), st.close()]))
+useTestEnv({ appwriteUrl: aw.url, stripeUrl: st.url })
+const { Query, createDocument, createDocuments, getDocument, updateDocument, listDocuments, listAllDocuments } = await import(
+  '../server/services/appwriteAdmin.js'
+)
+
+const idsOf = (collection, prefix) => [...aw.docs(collection).keys()].filter((id) => id.startsWith(prefix)).sort()
+const cell = (id, over = {}) => ({
+  $id: id,
+  featureId: 'f1',
+  ressourceId: 'r1',
+  bookingId: 'b1',
+  zelle: '2026-10-05T10:00:00.000Z',
+  bis: '2026-10-05T10:30:00.000Z',
+  ...over,
+})
+const rawDocs = (mock, collection) => `${mock.url}/databases/woms-database/collections/${collection}/documents`
+const postJson = (url, body) => fetch(url, { method: 'POST', headers: { 'content-type': 'application/json' }, body: JSON.stringify(body) })
+
+test('Query-Helfer bauen die Appwrite-Abfragen', () => {
+  assert.deepEqual(Query.between('startsAt', 'a', 'b'), { method: 'between', attribute: 'startsAt', values: ['a', 'b'] })
+  assert.deepEqual(Query.greaterThanEqual('startsAt', 'a'), { method: 'greaterThanEqual', attribute: 'startsAt', values: ['a'] })
+  assert.deepEqual(Query.lessThanEqual('startsAt', 'b'), { method: 'lessThanEqual', attribute: 'startsAt', values: ['b'] })
+  assert.deepEqual(Query.cursorAfter('doc1'), { method: 'cursorAfter', values: ['doc1'] })
+})
+
+test('Bulk-Create legt 3 Dokumente in einer Anfrage an', async () => {
+  const created = await createDocuments('termineClaims', [cell('t2_a1'), cell('t2_a2', { bookingId: 'b2' }), cell('t2_a3')])
+  assert.deepEqual(created.map((d) => d.$id), ['t2_a1', 't2_a2', 't2_a3'])
+  assert.deepEqual(idsOf('termineClaims', 't2_a'), ['t2_a1', 't2_a2', 't2_a3'])
+  const second = await getDocument('termineClaims', 't2_a2')
+  assert.equal(second.bookingId, 'b2')
+  assert.equal(second.featureId, 'f1')
+})
+
+test('Bulk-Create ohne Dokumente sendet nichts', async () => {
+  assert.deepEqual(await createDocuments('termineClaims', []), [])
+})
+
+test('Bulk mit vorhandener ID: 409 und nichts geschrieben', async () => {
+  await createDocument('termineClaims', cell('t2_b2', { bookingId: 'alt' }), 't2_b2')
+  const before = [...aw.docs('termineClaims').entries()].length
+  await assert.rejects(
+    createDocuments('termineClaims', [cell('t2_b1'), cell('t2_b2', { bookingId: 'neu' }), cell('t2_b3')]),
+    (err) => err.status === 409 && err.type === 'document_already_exists'
+  )
+  assert.deepEqual(idsOf('termineClaims', 't2_b'), ['t2_b2'])
+  assert.equal(aw.docs('termineClaims').size, before)
+  assert.equal(aw.docs('termineClaims').get('t2_b2').bookingId, 'alt')
+})
+
+test('Bulk mit doppelter ID innerhalb der Anfrage: 409 und nichts geschrieben', async () => {
+  await assert.rejects(createDocuments('termineClaims', [cell('t2_c1'), cell('t2_c1')]), (err) => err.status === 409)
+  assert.deepEqual(idsOf('termineClaims', 't2_c'), [])
+})
+
+test('Bulk mit unbekanntem Attribut oder ungueltigem Datum: 400 und nichts geschrieben', async () => {
+  await assert.rejects(
+    createDocuments('termineClaims', [cell('t2_d1'), cell('t2_d2', { bogus: 1 })]),
+    (err) => err.status === 400 && /Unknown attribute: "bogus"/.test(err.message)
+  )
+  await assert.rejects(createDocuments('termineClaims', [cell('t2_d3'), cell('t2_d4', { zelle: '' })]), (err) => err.status === 400)
+  await assert.rejects(createDocuments('termineClaims', [cell('t2_d5'), { featureId: 'ohne-id' }]), (err) => err.status === 400)
+  assert.deepEqual(idsOf('termineClaims', 't2_d'), [])
+})
+
+test('Bulk ueber 100 Dokumente: 400 wie Appwrite, nichts geschrieben', async () => {
+  const many = Array.from({ length: 101 }, (_, i) => cell(`t2_e${String(i).padStart(3, '0')}`))
+  await assert.rejects(createDocuments('termineClaims', many), (err) => err.status === 400)
+  assert.deepEqual(idsOf('termineClaims', 't2_e'), [])
+  const exactly = await createDocuments('termineClaims', many.slice(0, 100))
+  assert.equal(exactly.length, 100)
+})
+
+test('between ist inklusiv, greaterThanEqual/lessThanEqual ebenso', async () => {
+  const starts = ['10:00', '10:30', '11:00', '11:30', '12:00']
+  for (const [i, t] of starts.entries()) {
+    await createDocument('termineBookings', { featureId: 'f_between', startsAt: `2026-10-05T${t}:00.000Z`, status: 'bestaetigt' }, `t2_bk${i}`)
+  }
+  const inFeature = Query.equal('featureId', 'f_between')
+  const order = Query.orderAsc('startsAt')
+  const between = await listDocuments('termineBookings', [inFeature, Query.between('startsAt', '2026-10-05T10:30:00.000Z', '2026-10-05T11:30:00.000Z'), order])
+  assert.deepEqual(between.map((d) => d.$id), ['t2_bk1', 't2_bk2', 't2_bk3'])
+  // dieselben Zeitpunkte in anderer Schreibweise (Berlin, Sommerzeit +02:00)
+  const offset = await listDocuments('termineBookings', [inFeature, Query.between('startsAt', '2026-10-05T12:30:00+02:00', '2026-10-05T13:30:00+02:00'), order])
+  assert.deepEqual(offset.map((d) => d.$id), ['t2_bk1', 't2_bk2', 't2_bk3'])
+  const from = await listDocuments('termineBookings', [inFeature, Query.greaterThanEqual('startsAt', '2026-10-05T11:30:00.000Z'), order])
+  assert.deepEqual(from.map((d) => d.$id), ['t2_bk3', 't2_bk4'])
+  const until = await listDocuments('termineBookings', [inFeature, Query.lessThanEqual('startsAt', '2026-10-05T10:30:00.000Z'), order])
+  assert.deepEqual(until.map((d) => d.$id), ['t2_bk0', 't2_bk1'])
+  // greaterThan/lessThan bleiben exklusiv
+  const later = await listDocuments('termineBookings', [inFeature, Query.greaterThan('startsAt', '2026-10-05T11:30:00Z'), order])
+  assert.deepEqual(later.map((d) => d.$id), ['t2_bk4'])
+  const equal = await listDocuments('termineBookings', [inFeature, Query.equal('startsAt', '2026-10-05T13:00:00+02:00')])
+  assert.deepEqual(equal.map((d) => d.$id), ['t2_bk2'])
+})
+
+test('cursorAfter liefert die Dokumente nach dem genannten', async () => {
+  for (let i = 0; i < 6; i += 1) aw.seed('termineClaims', cell(`t2_f${i}`, { featureId: 'f_cursor' }))
+  const page = await listDocuments('termineClaims', [Query.equal('featureId', 'f_cursor'), Query.orderAsc('$id'), Query.cursorAfter('t2_f1'), Query.limit(3)])
+  assert.deepEqual(page.map((d) => d.$id), ['t2_f2', 't2_f3', 't2_f4'])
+  await assert.rejects(listDocuments('termineClaims', [Query.cursorAfter('gibt-es-nicht'), Query.limit(3)]), (err) => err.status === 400)
+})
+
+test('listAllDocuments laedt ueber 3 Seiten, in $id-Reihenfolge und nur die passenden', async () => {
+  for (let i = 0; i < 25; i += 1) aw.seed('termineClaims', cell(`t2_g${String(i).padStart(2, '0')}`, { featureId: 'f_pages' }))
+  for (let i = 0; i < 7; i += 1) aw.seed('termineClaims', cell(`t2_g_fremd${i}`, { featureId: 'f_andere' }))
+  const realFetch = globalThis.fetch
+  let requests = 0
+  globalThis.fetch = (...args) => {
+    requests += 1
+    return realFetch(...args)
+  }
+  let all
+  try {
+    all = await listAllDocuments('termineClaims', [Query.equal('featureId', 'f_pages')], { pageSize: 10 })
+  } finally {
+    globalThis.fetch = realFetch
+  }
+  assert.equal(requests, 3)
+  assert.equal(all.length, 25)
+  assert.deepEqual(all.map((d) => d.$id), Array.from({ length: 25 }, (_, i) => `t2_g${String(i).padStart(2, '0')}`))
+})
+
+test('listAllDocuments: Vielfaches der Seitengroesse, leere Treffermenge und Standard-Seitengroesse', async () => {
+  for (let i = 0; i < 20; i += 1) aw.seed('termineClaims', cell(`t2_h${String(i).padStart(2, '0')}`, { featureId: 'f_vielfach' }))
+  assert.equal((await listAllDocuments('termineClaims', [Query.equal('featureId', 'f_vielfach')], { pageSize: 10 })).length, 20)
+  assert.deepEqual(await listAllDocuments('termineClaims', [Query.equal('featureId', 'f_leer')]), [])
+  // 30 Treffer > defaultLimit 25: nur mit eigenem limit-Aufruf vollstaendig
+  for (let i = 0; i < 30; i += 1) aw.seed('termineClaims', cell(`t2_h_x${String(i).padStart(2, '0')}`, { featureId: 'f_dreissig' }))
+  assert.equal((await listAllDocuments('termineClaims', [Query.equal('featureId', 'f_dreissig')])).length, 30)
+})
+
+test('listAllDocuments: mehr Treffer als max ist ein Fehler, genau max nicht', async () => {
+  for (let i = 0; i < 21; i += 1) aw.seed('termineClaims', cell(`t2_i${String(i).padStart(2, '0')}`, { featureId: 'f_max' }))
+  const filter = [Query.equal('featureId', 'f_max')]
+  await assert.rejects(listAllDocuments('termineClaims', filter, { pageSize: 10, max: 20 }), /mehr als 20 /)
+  assert.equal((await listAllDocuments('termineClaims', filter, { pageSize: 10, max: 21 })).length, 21)
+  await assert.rejects(listAllDocuments('termineClaims', filter, { pageSize: 0 }), /pageSize/)
+})
+
+test('defaultLimit 25 liefert ohne limit-Abfrage 25 von 30', async () => {
+  for (let i = 0; i < 30; i += 1) aw.seed('termineOutbox', { $id: `t2_j${String(i).padStart(2, '0')}`, featureId: 'f_limit', status: 'wartet' })
+  const filter = [Query.equal('featureId', 'f_limit')]
+  assert.equal((await listDocuments('termineOutbox', filter)).length, 25)
+  assert.equal((await listDocuments('termineOutbox', [...filter, Query.limit(30)])).length, 30)
+  assert.equal((await listDocuments('termineOutbox', [...filter, Query.limit(5)])).length, 5)
+})
+
+test('Datum mit Z kommt als +00:00 zurueck (Anlegen, Aendern, Bulk, Seed)', async () => {
+  const made = await createDocument('termineBookings', { featureId: 'f_dt', startsAt: '2026-10-05T10:00:00Z', endsAt: '2026-10-05T12:30:00+02:00', status: 'x' }, 't2_dt1')
+  assert.equal(made.startsAt, '2026-10-05T10:00:00.000+00:00')
+  assert.equal(made.endsAt, '2026-10-05T10:30:00.000+00:00')
+  assert.equal((await getDocument('termineBookings', 't2_dt1')).startsAt, '2026-10-05T10:00:00.000+00:00')
+  const patched = await updateDocument('termineBookings', 't2_dt1', { heldUntil: '2026-10-05T09:59:00.5Z' })
+  assert.equal(patched.heldUntil, '2026-10-05T09:59:00.500+00:00')
+  assert.equal(patched.startsAt, '2026-10-05T10:00:00.000+00:00')
+  const [bulk] = await createDocuments('termineClaims', [cell('t2_dt2', { zelle: '2026-10-05T10:05:00Z' })])
+  assert.equal(bulk.zelle, '2026-10-05T10:05:00.000+00:00')
+  assert.equal(bulk.bis, '2026-10-05T10:30:00.000+00:00')
+  aw.seed('termineBookings', { $id: 't2_dt3', startsAt: '2026-10-05T10:00:00Z' })
+  assert.equal(aw.docs('termineBookings').get('t2_dt3').startsAt, '2026-10-05T10:00:00.000+00:00')
+  // Textfelder, die zufaellig wie ein Datum aussehen, bleiben unveraendert
+  const text = await createDocument('termineBookings', { gastNachricht: '2026-10-05T10:00:00Z' }, 't2_dt4')
+  assert.equal(text.gastNachricht, '2026-10-05T10:00:00Z')
+  // null bleibt erlaubt (optionales Datumsfeld leeren)
+  const cleared = await updateDocument('termineBookings', 't2_dt1', { heldUntil: null })
+  assert.equal(cleared.heldUntil, null)
+})
+
+test('leeres oder unlesbares Datum: 400 beim Anlegen und Aendern', async () => {
+  await assert.rejects(createDocument('termineBookings', { startsAt: '' }, 't2_dt5'), (err) => err.status === 400)
+  await assert.rejects(createDocument('termineBookings', { startsAt: 'morgen' }, 't2_dt6'), (err) => err.status === 400)
+  await assert.rejects(updateDocument('termineBookings', 't2_dt1', { endsAt: '' }), (err) => err.status === 400)
+  assert.equal(aw.docs('termineBookings').has('t2_dt5'), false)
+  assert.equal((await getDocument('termineBookings', 't2_dt1')).endsAt, '2026-10-05T10:30:00.000+00:00')
+})
+
+test('Nachbau ohne Optionen verhaelt sich wie bisher', async () => {
+  const col = rawDocs(plain, 'irgendwas')
+  for (let i = 0; i < 30; i += 1) {
+    const res = await postJson(col, { documentId: `p${String(i).padStart(2, '0')}`, data: { n: i, am: '2026-10-05T10:00:00Z' } })
+    assert.equal(res.status, 201)
+  }
+  const listed = await (await fetch(col)).json()
+  assert.equal(listed.documents.length, 30)
+  assert.equal(listed.documents[0].am, '2026-10-05T10:00:00Z')
+  const queries = [{ method: 'between', attribute: 'n', values: [5, 7] }, { method: 'orderAsc', attribute: 'n' }]
+  const between = await (await fetch(`${col}?${queries.map((q) => `queries[]=${encodeURIComponent(JSON.stringify(q))}`).join('&')}`)).json()
+  assert.deepEqual(between.documents.map((d) => d.n), [5, 6, 7])
+  const bulk = await postJson(col, { documents: [{ $id: 'q1', n: 100 }, { $id: 'q2', n: 101 }] })
+  assert.equal(bulk.status, 201)
+  assert.equal((await postJson(col, { documents: [{ $id: 'q3', n: 102 }, { $id: 'q1', n: 103 }] })).status, 409)
+  assert.equal(plain.docs('irgendwas').has('q3'), false)
+})
+
+test('testApp.send ruft beliebige Methoden auf', async () => {
+  const { startTestApp, send } = await import('./support/testApp.js')
+  const router = express.Router()
+  router.put('/echo', (req, res) => res.json({ method: req.method, body: req.body, via: req.get('x-test') }))
+  const app = await startTestApp({ '/t': router })
+  try {
+    const res = await send('PUT', '/t/echo', { body: { a: 1 }, headers: { 'x-test': 'ja' } })
+    assert.equal(res.status, 200)
+    assert.deepEqual(res.body, { method: 'PUT', body: { a: 1 }, via: 'ja' })
+  } finally {
+    await app.close()
+  }
+})
diff --git a/test/support/appwriteMock.js b/test/support/appwriteMock.js
index 391fbf3..facd0ce 100644
--- a/test/support/appwriteMock.js
+++ b/test/support/appwriteMock.js
@@ -8,8 +8,19 @@ import http from 'node:http'
  * Anfang). failNext({ collection?, method?, status, message?, after? }) lässt die nächste passende Anfrage
  * mit diesem Status scheitern (Fehlerpfade wie "Appwrite nicht erreichbar" oder "Collection fehlt");
  * after = Zahl passender Anfragen, die vorher noch durchgehen (z. B. erst die zweite PATCH scheitert).
+ *
+ * Bulk-Create (POST .../documents mit { documents: [{ $id, ...felder }] }, 1 bis 100 Dokumente) ist alles oder
+ * nichts: vorhandene oder doppelte $id => 409, ungueltige $id, unbekanntes Attribut oder ungueltiges Datum => 400,
+ * dann ist nichts geschrieben. Abfragen: equal, greaterThan(Equal), lessThan(Equal), between (inklusiv), orderAsc/
+ * orderDesc, limit, cursorAfter. Zwei Werte, die beide wie "YYYY-MM-DDT..." aussehen, vergleicht er als Zeitpunkte
+ * (Schreibweise Z, +00:00, +02:00 ist egal), alle anderen wie bisher.
+ *
+ * Optionen (ohne sie verhaelt sich der Nachbau wie zuvor):
+ *   datetimes      { collection: ['feld', ...] } Datumsfelder; beim Schreiben (Anlegen, Aendern, Bulk, seed) wie
+ *                  Appwrite auf "...000+00:00" (UTC) normalisiert, '' oder Unlesbares => 400, null bleibt erlaubt
+ *   defaultLimit   Zahl: gilt ohne limit-Abfrage wie Appwrites 25 (Termine-Tests: 25), null = unbegrenzt
  */
-export async function startAppwriteMock({ schema = {} } = {}) {
+export async function startAppwriteMock({ schema = {}, datetimes = {}, defaultLimit = null } = {}) {
   const collections = new Map()
   let sequence = 0
   let pendingFailure = null
@@ -34,6 +45,8 @@ export async function startAppwriteMock({ schema = {} } = {}) {
     },
   ]
 
+  const documentExists = [409, { message: 'Document with the requested ID already exists.', code: 409, type: 'document_already_exists' }]
+
   const docs = (collection) => {
     if (!collections.has(collection)) collections.set(collection, new Map())
     return collections.get(collection)
@@ -46,9 +59,62 @@ export async function startAppwriteMock({ schema = {} } = {}) {
 
   const seed = (collection, doc) => {
     if (!doc?.$id) throw new Error('seed: $id fehlt')
-    docs(collection).set(doc.$id, stamp(doc, collection))
+    const [normalized, badDate] = normalizeDates(collection, doc)
+    if (badDate) throw new Error(`seed: ${collection}.${badDate} ist kein gueltiges Datum`)
+    docs(collection).set(doc.$id, stamp(normalized, collection))
   }
 
+  // Zeitpunkt eines Textes wie "2026-10-05T10:00:00Z" (ohne Zonenangabe gilt UTC); NaN, wenn es keiner ist
+  const isoStart = /^\d{4}-\d\d-\d\dT/
+  const hasZone = /(?:Z|[+-]\d\d(?::?\d\d)?)$/i
+  const instant = (value) => (typeof value === 'string' && isoStart.test(value) ? Date.parse(hasZone.test(value) ? value : `${value}Z`) : Number.NaN)
+
+  // Beide Seiten Zeitpunkte => deren Millisekunden, sonst die Werte selbst (Vergleich wie bisher)
+  const comparable = (a, b) => {
+    const x = instant(a)
+    const y = instant(b)
+    return Number.isNaN(x) || Number.isNaN(y) ? [a, b] : [x, y]
+  }
+  const same = (a, b) => {
+    const [x, y] = comparable(a, b)
+    return x === y
+  }
+  const greater = (a, b) => {
+    const [x, y] = comparable(a, b)
+    return x > y
+  }
+  const less = (a, b) => {
+    const [x, y] = comparable(a, b)
+    return x < y
+  }
+  const atLeast = (a, b) => {
+    const [x, y] = comparable(a, b)
+    return x >= y
+  }
+  const atMost = (a, b) => {
+    const [x, y] = comparable(a, b)
+    return x <= y
+  }
+
+  // Datumsfelder der Collection wie Appwrite speichern: UTC mit Millisekunden und "+00:00". Liefert
+  // [Daten, Schluessel des ersten ungueltigen Datums | null]
+  const normalizeDates = (collection, data) => {
+    const keys = datetimes[collection]
+    if (!keys?.length) return [data, null]
+    const out = { ...data }
+    for (const key of keys) {
+      const value = out[key]
+      if (value === undefined || value === null) continue
+      let ms = Number.NaN
+      if (value instanceof Date) ms = value.getTime()
+      else if (typeof value === 'string') ms = isoStart.test(value) ? instant(value) : /^\d{4}-\d\d-\d\d$/.test(value) ? Date.parse(value) : Number.NaN
+      if (Number.isNaN(ms)) return [data, key]
+      out[key] = new Date(ms).toISOString().replace('Z', '+00:00')
+    }
+    return [out, null]
+  }
+  const invalidDate = (key) => [400, { message: `Invalid document structure: Attribute "${key}" has invalid format. Value must be a valid date`, code: 400, type: 'document_invalid_structure' }]
+
   const unknownAttribute = (collection, data) => {
     const allowed = schema[collection]
     if (!allowed) return null
@@ -57,34 +123,48 @@ export async function startAppwriteMock({ schema = {} } = {}) {
 
   const matches = (doc, query) => {
     const value = doc[query.attribute]
+    const [first, last] = query.values || []
     switch (query.method) {
       case 'equal':
-        return query.values.includes(value)
+        return query.values.some((candidate) => same(value, candidate))
       case 'greaterThan':
-        return value > query.values[0]
+        return greater(value, first)
+      case 'greaterThanEqual':
+        return atLeast(value, first)
       case 'lessThan':
-        return value < query.values[0]
+        return less(value, first)
+      case 'lessThanEqual':
+        return atMost(value, first)
+      case 'between':
+        return atLeast(value, first) && atMost(value, last)
       default:
         return true
     }
   }
 
+  const supportedQueries = ['equal', 'greaterThan', 'greaterThanEqual', 'lessThan', 'lessThanEqual', 'between', 'orderAsc', 'orderDesc', 'limit', 'cursorAfter']
+
   const list = (collection, rawQueries) => {
     const queries = rawQueries.map((q) => JSON.parse(q))
-    const unsupported = queries.find((q) => !['equal', 'greaterThan', 'lessThan', 'orderAsc', 'orderDesc', 'limit'].includes(q.method))
+    const unsupported = queries.find((q) => !supportedQueries.includes(q.method))
     if (unsupported) return [400, { message: `Query ${unsupported.method} wird nicht nachgebaut`, code: 400 }]
-    let result = [...docs(collection).values()].filter((doc) => queries.every((q) => matches(doc, q)))
+    // cursorAfter: das Dokument mit dieser ID muss es geben (es muss aber nicht zu den Filtern passen)
+    const cursorId = queries.find((q) => q.method === 'cursorAfter')?.values[0]
+    if (cursorId !== undefined && !docs(collection).has(cursorId)) {
+      return [400, { message: 'The cursor is invalid. This can happen if the item represented by the cursor has been deleted.', code: 400, type: 'general_cursor_not_found' }]
+    }
+    let result = [...docs(collection).values()].filter((doc) => doc.$id === cursorId || queries.every((q) => matches(doc, q)))
     for (const q of queries.filter((q) => q.method === 'orderAsc' || q.method === 'orderDesc')) {
       const dir = q.method === 'orderAsc' ? 1 : -1
       result.sort((a, b) => {
-        const x = a[q.attribute]
-        const y = b[q.attribute]
+        const [x, y] = comparable(a[q.attribute], b[q.attribute])
         if (x === y) return (a.$seq - b.$seq) * dir
         return (x > y ? 1 : -1) * dir
       })
     }
-    const limit = queries.find((q) => q.method === 'limit')
-    if (limit) result = result.slice(0, limit.values[0])
+    if (cursorId !== undefined) result = result.slice(result.findIndex((doc) => doc.$id === cursorId) + 1)
+    const limit = queries.find((q) => q.method === 'limit')?.values[0] ?? defaultLimit
+    if (limit !== null) result = result.slice(0, limit)
     return [200, { total: result.length, documents: result.map(publicDoc) }]
   }
 
@@ -162,6 +242,33 @@ export async function startAppwriteMock({ schema = {} } = {}) {
     return null
   }
 
+  // Bulk-Create (Appwrite 1.8.1, API-Schluessel): alles oder nichts. Erst jedes Dokument pruefen (400), dann auf
+  // vorhandene oder doppelte IDs (409); geschrieben wird erst, wenn alles durch ist. Anders als Appwrite (das eine
+  // fehlende $id selbst vergibt) verlangt der Nachbau die $id, die Belegungszellen brauchen feste IDs.
+  const createMany = (collection, documents) => {
+    if (documents.length < 1 || documents.length > 100) {
+      return [400, { message: 'Invalid `documents` param: Value must be a valid array and contain between 1 and 100 items', code: 400, type: 'general_argument_invalid' }]
+    }
+    const prepared = []
+    for (const document of documents) {
+      if (!document || typeof document !== 'object' || Array.isArray(document) || !validDocumentId(document.$id)) return invalidDocumentId
+      const bad = unknownAttribute(collection, document)
+      if (bad) return [400, { message: `Invalid document structure: Unknown attribute: "${bad}"`, code: 400 }]
+      const [dated, badDate] = normalizeDates(collection, document)
+      if (badDate) return invalidDate(badDate)
+      prepared.push(dated)
+    }
+    const store = docs(collection)
+    const ids = new Set()
+    for (const { $id } of prepared) {
+      if (store.has($id) || ids.has($id)) return documentExists
+      ids.add($id)
+    }
+    const created = prepared.map((document) => stamp(document, collection))
+    for (const document of created) store.set(document.$id, document)
+    return [201, { total: created.length, documents: created.map(publicDoc) }]
+  }
+
   const handle = async (req) => {
     const url = new URL(req.url, 'http://127.0.0.1')
     const auth = await handleAuth(req, url)
@@ -211,14 +318,16 @@ export async function startAppwriteMock({ schema = {} } = {}) {
 
     if (!id && req.method === 'GET') return list(collection, url.searchParams.getAll('queries[]'))
     if (!id && req.method === 'POST') {
-      const { documentId, data = {} } = await readBody(req)
+      const body = await readBody(req)
+      if (Array.isArray(body.documents)) return createMany(collection, body.documents)
+      const { documentId, data = {} } = body
       if (!validDocumentId(documentId)) return invalidDocumentId
-      if (store.has(documentId)) {
-        return [409, { message: 'Document with the requested ID already exists.', code: 409, type: 'document_already_exists' }]
-      }
+      if (store.has(documentId)) return documentExists
       const bad = unknownAttribute(collection, data)
       if (bad) return [400, { message: `Invalid document structure: Unknown attribute: "${bad}"`, code: 400 }]
-      const doc = stamp({ ...data, $id: documentId }, collection)
+      const [dated, badDate] = normalizeDates(collection, data)
+      if (badDate) return invalidDate(badDate)
+      const doc = stamp({ ...dated, $id: documentId }, collection)
       store.set(documentId, doc)
       return [201, publicDoc(doc)]
     }
@@ -228,7 +337,9 @@ export async function startAppwriteMock({ schema = {} } = {}) {
       const { data = {} } = await readBody(req)
       const bad = unknownAttribute(collection, data)
       if (bad) return [400, { message: `Invalid document structure: Unknown attribute: "${bad}"`, code: 400 }]
-      const doc = { ...store.get(id), ...data, $updatedAt: new Date().toISOString() }
+      const [dated, badDate] = normalizeDates(collection, data)
+      if (badDate) return invalidDate(badDate)
+      const doc = { ...store.get(id), ...dated, $updatedAt: new Date().toISOString() }
       store.set(id, doc)
       return [200, publicDoc(doc)]
     }
diff --git a/test/support/testApp.js b/test/support/testApp.js
index c0ce0f1..12fda08 100644
--- a/test/support/testApp.js
+++ b/test/support/testApp.js
@@ -69,7 +69,8 @@ export async function startTestApp(routers = {}) {
   return { url: baseUrl, close: () => new Promise((resolve) => server.close(resolve)) }
 }
 
-async function request(method, path, { body, cookie, headers = {} } = {}) {
+/** Anfrage an die zuletzt gestartete App (beliebige Methode) -> { status, body, headers }; body ist geparstes JSON, sonst Text. */
+export async function send(method, path, { body, cookie, headers = {} } = {}) {
   if (!baseUrl) throw new Error('testApp: startTestApp() zuerst aufrufen')
   const res = await fetch(baseUrl + path, {
     method,
@@ -92,7 +93,7 @@ async function request(method, path, { body, cookie, headers = {} } = {}) {
 }
 
 /** GET -> { status, body } */
-export const rawGet = (path, opts = {}) => request('GET', path, opts)
+export const rawGet = (path, opts = {}) => send('GET', path, opts)
 
 /** GET -> JSON-Body; ab Status 400 fliegt ein Fehler mit err.status und err.body. */
 export async function get(path, opts = {}) {
@@ -107,7 +108,7 @@ export async function get(path, opts = {}) {
 }
 
 /** POST mit JSON-Body -> { status, body } */
-export const post = (path, body, opts = {}) => request('POST', path, { ...opts, body })
+export const post = (path, body, opts = {}) => send('POST', path, { ...opts, body })
 
 // Signiert wie Stripe (whsec_test aus useTestEnv); der Schluessel wird nie fuer Netzaufrufe benutzt
 const webhookSigner = new Stripe('sk_test_fake')
@@ -116,5 +117,5 @@ const webhookSigner = new Stripe('sk_test_fake')
 export function postWebhook(event, { path = '/api/abo/webhook', secret = config.stripe.webhookSecret || 'whsec_test' } = {}) {
   const payload = JSON.stringify(event)
   const stripeSignature = webhookSigner.webhooks.generateTestHeaderString({ payload, secret })
-  return request('POST', path, { body: payload, headers: { 'stripe-signature': stripeSignature } })
+  return send('POST', path, { body: payload, headers: { 'stripe-signature': stripeSignature } })
 }