diff --git a/server/services/pushTimeEntry.js b/server/services/pushTimeEntry.js
new file mode 100644
index 0000000..cf40bae
--- /dev/null
+++ b/server/services/pushTimeEntry.js
@@ -0,0 +1,75 @@
+import { config } from '../config.js'
+import { withLocks } from './keyedLock.js'
+import { getDocument, updateDocument } from './appwriteAdmin.js'
+
+/**
+ * Zeit fuer ein Git-Push-Arbeitsblatt eintragen (Push-Zeitmail). Ergebnis wie "Zeit nachtragen" in
+ * WOMS: Startzeit = Push-Zeit (Endzeit) minus Dauer, totalTime = Minuten, isComment = false.
+ * Eine schon eingetragene Zeit wird nie ueberschrieben - Aendern geht nur in WOMS.
+ */
+
+export const MAX_MINUTES = 720
+
+const pad = (n) => String(n).padStart(2, '0')
+
+/** Wand-Uhrzeit rueckwaerts rechnen ('tt.mm.jjjj', 'hhmm'); reine Kalenderrechnung, ohne Zeitzone. */
+export function startFromEnd(endDate, endTime, minutes) {
+  const [day, month, year] = String(endDate).split('.').map(Number)
+  const hours = Number(String(endTime).slice(0, 2))
+  const mins = Number(String(endTime).slice(2, 4))
+  const start = new Date(Date.UTC(year, month - 1, day, hours, mins) - minutes * 60 * 1000)
+  return {
+    startDate: `${pad(start.getUTCDate())}.${pad(start.getUTCMonth() + 1)}.${start.getUTCFullYear()}`,
+    startTime: `${pad(start.getUTCHours())}${pad(start.getUTCMinutes())}`,
+  }
+}
+
+/** Git-Push ohne eingetragene Zeit (wie needsTimeEntry in WOMS) */
+export function needsTimeEntry(ws) {
+  return ws?.serviceType === 'GIT' && !(ws.startTime && Number(ws.totalTime) > 0)
+}
+
+/** Ganze Minuten 1-720 aus Formular/Query, sonst null */
+export function parseMinutes(raw) {
+  if (raw === null || raw === undefined) return null
+  const text = String(raw).trim()
+  if (!/^\d+$/.test(text)) return null
+  const value = Number(text)
+  return value >= 1 && value <= MAX_MINUTES ? value : null
+}
+
+/** 15 -> '15 Min', 60 -> '1 Std', 90 -> '1,5 Std', 130 -> '2 Std 10 Min' */
+export function formatMinutes(min) {
+  const total = Number(min) || 0
+  if (total < 60) return `${total} Min`
+  const hours = Math.floor(total / 60)
+  const rest = total % 60
+  if (rest === 0) return `${hours} Std`
+  if (rest === 30) return `${hours},5 Std`
+  return `${hours} Std ${rest} Min`
+}
+
+/**
+ * @returns {Promise<{ status: 'saved' | 'already' | 'missing' | 'not_git', worksheet?: object }>}
+ */
+export async function applyPushTime(worksheetId, minutes) {
+  return withLocks([`ws-time:${worksheetId}`], async () => {
+    let ws
+    try {
+      ws = await getDocument(config.collections.worksheets, worksheetId)
+    } catch {
+      return { status: 'missing' }
+    }
+    if (ws.serviceType !== 'GIT') return { status: 'not_git', worksheet: ws }
+    if (!needsTimeEntry(ws)) return { status: 'already', worksheet: ws }
+
+    const { startDate, startTime } = startFromEnd(ws.endDate, ws.endTime, minutes)
+    const worksheet = await updateDocument(config.collections.worksheets, worksheetId, {
+      startDate,
+      startTime,
+      totalTime: minutes,
+      isComment: false,
+    })
+    return { status: 'saved', worksheet }
+  })
+}
diff --git a/test/pushTimeEntry.test.js b/test/pushTimeEntry.test.js
new file mode 100644
index 0000000..a3324ba
--- /dev/null
+++ b/test/pushTimeEntry.test.js
@@ -0,0 +1,74 @@
+import { test, before, after } from 'node:test'
+import assert from 'node:assert/strict'
+import { startFakeAppwrite } from './helpers/fakeAppwrite.js'
+
+let fake
+let startFromEnd, needsTimeEntry, parseMinutes, formatMinutes, applyPushTime
+
+const openGit = (id) => ({
+  $id: id, wsid: '100200', woid: '100118', serviceType: 'GIT',
+  endDate: '30.09.2026', endTime: '1646', startDate: '30.09.2026', startTime: '', totalTime: 0, isComment: true,
+})
+
+before(async () => {
+  fake = await startFakeAppwrite({
+    seed: {
+      worksheets: [
+        openGit('ws1'),
+        openGit('ws-race'),
+        { $id: 'remote1', serviceType: 'Remote', startTime: '', totalTime: 0 },
+      ],
+    },
+  })
+  Object.assign(process.env, { APPWRITE_ENDPOINT: fake.endpoint, APPWRITE_API_KEY: 'test-key' })
+  ;({ startFromEnd, needsTimeEntry, parseMinutes, formatMinutes, applyPushTime } = await import(
+    '../server/services/pushTimeEntry.js'
+  ))
+})
+
+after(async () => {
+  await fake.close()
+})
+
+test('startFromEnd: normal, über Mitternacht, Jahres- und Schalttag-Grenze', () => {
+  assert.deepEqual(startFromEnd('30.09.2026', '1646', 60), { startDate: '30.09.2026', startTime: '1546' })
+  assert.deepEqual(startFromEnd('01.10.2026', '0020', 45), { startDate: '30.09.2026', startTime: '2335' })
+  assert.deepEqual(startFromEnd('01.01.2027', '0010', 30), { startDate: '31.12.2026', startTime: '2340' })
+  assert.deepEqual(startFromEnd('01.03.2028', '0000', 1), { startDate: '29.02.2028', startTime: '2359' })
+})
+
+test('needsTimeEntry', () => {
+  assert.equal(needsTimeEntry({ serviceType: 'GIT', startTime: '', totalTime: 0 }), true)
+  assert.equal(needsTimeEntry({ serviceType: 'GIT', startTime: '1500', totalTime: 45 }), false)
+  assert.equal(needsTimeEntry({ serviceType: 'Remote', startTime: '', totalTime: 0 }), false)
+})
+
+test('parseMinutes: ganze Minuten 1–720', () => {
+  assert.equal(parseMinutes('45'), 45)
+  assert.equal(parseMinutes(720), 720)
+  for (const bad of ['1.5', '0', '721', '', 'abc', undefined, null, '-5', '45abc']) {
+    assert.equal(parseMinutes(bad), null, String(bad))
+  }
+})
+
+test('formatMinutes', () => {
+  assert.equal(formatMinutes(15), '15 Min')
+  assert.equal(formatMinutes(60), '1 Std')
+  assert.equal(formatMinutes(90), '1,5 Std')
+  assert.equal(formatMinutes(130), '2 Std 10 Min')
+})
+
+test('applyPushTime: speichert einmal, überschreibt nie', async () => {
+  assert.equal((await applyPushTime('ws1', 60)).status, 'saved')
+  const ws = fake.get('worksheets', 'ws1')
+  assert.deepEqual([ws.startDate, ws.startTime, ws.totalTime, ws.isComment], ['30.09.2026', '1546', 60, false])
+  assert.equal((await applyPushTime('ws1', 30)).status, 'already')
+  assert.equal(fake.get('worksheets', 'ws1').totalTime, 60)
+  assert.equal((await applyPushTime('gibtsnicht', 30)).status, 'missing')
+  assert.equal((await applyPushTime('remote1', 30)).status, 'not_git')
+})
+
+test('gleichzeitig: nur einer speichert', async () => {
+  const results = await Promise.all([applyPushTime('ws-race', 30), applyPushTime('ws-race', 90)])
+  assert.deepEqual(results.map((r) => r.status).sort(), ['already', 'saved'])
+})