claude · Oct 20, 2026
diff --git a/...ns/directus-extension-programmierbar-bundle/src/invoice-lifecycle/__tests__/index.test.ts b/...ns/directus-extension-programmierbar-bundle/src/invoice-lifecycle/__tests__/index.test.ts
@@ -61,7 +61,7 @@ const BASE_ORDER = {
     is_internal: false,
 }
 
-const CONFERENCE = { id: 'conf-1', title: 'programmier.con 2026', start_on: '2026-03-01' }
+const CONFERENCE = { id: 'conf-1', title: 'programmier.con 2026', start_on: '2026-03-01', end_on: '2026-03-02' }
 
 const ORIGINAL_SNAPSHOT = {
     order_id: 'order-1',
@@ -386,6 +386,11 @@ describe('invoice-lifecycle endpoint', () => {
             })
             // Snapshot taken from the order's CURRENT billing data.
             expect(correction.snapshot_json.company_name).toBe('Beispiel GmbH')
+            // Same service as the original: Leistungsdatum from the conference dates.
+            expect(correction.snapshot_json).toMatchObject({
+                service_date_start: '2026-03-01',
+                service_date_end: '2026-03-02',
+            })
 
             // The original document row stays byte-for-byte untouched.
             const original = db.ticket_invoices.find((r) => r.id === 'doc-original')
@@ -495,6 +500,9 @@ describe('invoice-lifecycle endpoint', () => {
                 vat_amount_cents: -3610,
                 total_gross_cents: -22610,
                 ticket_count: 2,
+                // The referenced snapshot predates the Leistungsdatum: falls back to the conference dates.
+                service_date_start: '2026-03-01',
+                service_date_end: '2026-03-02',
             })
 
             // The original document row stays untouched, nothing is deleted.

diff --git a/...us-cms/extensions/directus-extension-programmierbar-bundle/src/invoice-lifecycle/index.ts b/...us-cms/extensions/directus-extension-programmierbar-bundle/src/invoice-lifecycle/index.ts
@@ -12,6 +12,7 @@ import {
     negateInvoiceSnapshot,
     parseInvoiceSnapshot,
     renderAndUploadInvoice,
+    withServicePeriod,
     type InvoiceDocument,
     type RenderInvoiceResult,
 } from '../shared/invoice-service.js'
@@ -137,7 +138,9 @@ export default defineEndpoint(async (router: SandboxEndpointRouter, context) =>
         }
 
         const conferencesService = new ItemsService('conferences', { schema, accountability })
-        const conference = await conferencesService.readOne(order.conference, { fields: ['title', 'start_on'] })
+        const conference = await conferencesService.readOne(order.conference, {
+            fields: ['title', 'start_on', 'end_on'],
+        })
 
         if (!conference) {
             throw new HttpError(400, `Conference ${order.conference} not found`)
@@ -155,6 +158,7 @@ export default defineEndpoint(async (router: SandboxEndpointRouter, context) =>
             documents = await ensureInvoiceDocuments({
                 order,
                 conferenceTitle: conference.title,
+                servicePeriod: conference,
                 ticketCount,
                 invoicesService,
             })
@@ -243,7 +247,7 @@ export default defineEndpoint(async (router: SandboxEndpointRouter, context) =>
             throw new HttpError(400, `Invoice ${current.invoice_number} has been cancelled`)
         }
 
-        const snapshot = buildInvoiceSnapshot(ctx.order, ctx.conference.title, ctx.ticketCount)
+        const snapshot = buildInvoiceSnapshot(ctx.order, ctx.conference.title, ctx.ticketCount, ctx.conference)
 
         let rendered: RenderInvoiceResult
         if (current.type === 'correction') {
@@ -266,6 +270,7 @@ export default defineEndpoint(async (router: SandboxEndpointRouter, context) =>
                 referenceDate: new Date(predecessor.invoice_date),
                 filesService: ctx.filesService,
                 storageLocation: storageLocation(),
+                logger,
             })
         } else {
             rendered = await renderAndUploadInvoice({
@@ -275,6 +280,7 @@ export default defineEndpoint(async (router: SandboxEndpointRouter, context) =>
                 documentKind: 'invoice',
                 filesService: ctx.filesService,
                 storageLocation: storageLocation(),
+                logger,
             })
         }
 
@@ -321,7 +327,7 @@ export default defineEndpoint(async (router: SandboxEndpointRouter, context) =>
         const invoiceNumber = await generateInvoiceNumber(ctx.ordersService, ctx.invoicesService, conferenceYear)
         const invoiceDate = new Date()
 
-        const snapshot = buildInvoiceSnapshot(ctx.order, ctx.conference.title, ctx.ticketCount)
+        const snapshot = buildInvoiceSnapshot(ctx.order, ctx.conference.title, ctx.ticketCount, ctx.conference)
         const rendered = await renderAndUploadInvoice({
             snapshot,
             invoiceNumber,
@@ -331,6 +337,7 @@ export default defineEndpoint(async (router: SandboxEndpointRouter, context) =>
             referenceDate: new Date(current.invoice_date),
             filesService: ctx.filesService,
             storageLocation: storageLocation(),
+            logger,
         })
 
         const documentId = await ctx.invoicesService.createOne({
@@ -400,7 +407,9 @@ export default defineEndpoint(async (router: SandboxEndpointRouter, context) =>
         const invoiceNumber = await generateInvoiceNumber(ctx.ordersService, ctx.invoicesService, conferenceYear)
         const invoiceDate = new Date()
 
-        const snapshot = negateInvoiceSnapshot(referencedSnapshot)
+        // Same service as the referenced invoice, so the same Leistungsdatum; snapshots
+        // written before it was recorded fall back to the conference dates.
+        const snapshot = negateInvoiceSnapshot(withServicePeriod(referencedSnapshot, ctx.conference))
 
         const rendered = await renderAndUploadInvoice({
             snapshot,
@@ -411,6 +420,7 @@ export default defineEndpoint(async (router: SandboxEndpointRouter, context) =>
             referenceDate: new Date(current.invoice_date),
             filesService: ctx.filesService,
             storageLocation: storageLocation(),
+            logger,
         })
 
         const documentId = await ctx.invoicesService.createOne({

diff --git a/...s/directus-extension-programmierbar-bundle/src/shared/__tests__/invoice-generator.test.ts b/...s/directus-extension-programmierbar-bundle/src/shared/__tests__/invoice-generator.test.ts
@@ -4,10 +4,12 @@ import { describe, expect, jest, test } from '@jest/globals'
 import PDFDocument from 'pdfkit'
 import {
     fitHeadingFontSize,
+    generateInvoicePdf,
     HEADING_MAX_FONT_SIZE,
     HEADING_MIN_FONT_SIZE,
     HEADING_X,
     LOGO_RIGHT_EDGE,
+    type InvoiceData,
 } from '../invoice-generator.ts'
 
 // `import.meta.url` in the font loader cannot be parsed by Jest's CJS transform.
@@ -62,3 +64,57 @@ describe('invoice heading layout', () => {
         expect(fitHeadingFontSize(measure, 'x'.repeat(500), 100)).toBe(HEADING_MIN_FONT_SIZE)
     })
 })
+
+describe('invoice meta block', () => {
+    const BASE: InvoiceData = {
+        invoiceNumber: 'PB-CON26-001',
+        invoiceDate: '01.02.2026',
+        serviceDate: '25.–26.11.2026',
+        purchaserName: 'Erika Musterfrau',
+        purchaserEmail: 'erika@example.de',
+        companyName: null,
+        companyVatId: null,
+        billingAddressLine1: null,
+        billingAddressLine2: null,
+        billingCity: null,
+        billingPostalCode: null,
+        billingCountry: null,
+        conferenceTitle: 'programmier.con 2026',
+        ticketType: 'Regular',
+        ticketCount: 1,
+        unitPriceGrossCents: 11900,
+        subtotalCents: 10000,
+        discountAmountCents: 0,
+        vatAmountCents: 1900,
+        totalGrossCents: 11900,
+    }
+
+    /** Render the PDF and return every string passed to `doc.text`. */
+    async function renderedTexts(data: InvoiceData): Promise<string[]> {
+        const spy = jest.spyOn(PDFDocument.prototype, 'text')
+        try {
+            await generateInvoicePdf(data)
+            return spy.mock.calls.map((call) => String(call[0]))
+        } finally {
+            spy.mockRestore()
+        }
+    }
+
+    test.each([
+        ['invoice', {}],
+        ['correction', { referenceNumber: 'PB-CON26-000', referenceDate: '15.01.2026' }],
+        ['cancellation', { referenceNumber: 'PB-CON26-000', referenceDate: '15.01.2026' }],
+    ] as const)('a %s shows the Leistungsdatum (§ 14 Abs. 4 Nr. 6 UStG)', async (kind, reference) => {
+        const texts = await renderedTexts({ ...BASE, documentKind: kind, ...reference } as InvoiceData)
+
+        expect(texts).toContain('Rechnungsdatum: 01.02.2026')
+        expect(texts).toContain('Leistungsdatum: 25.–26.11.2026')
+    })
+
+    test('omits the Leistungsdatum line when no service date is known', async () => {
+        const texts = await renderedTexts({ ...BASE, serviceDate: null })
+
+        expect(texts.some((text) => text.startsWith('Leistungsdatum'))).toBe(false)
+        expect(texts).toContain('Fälligkeitsdatum: 01.02.2026')
+    })
+})
diff --git a/...ons/directus-extension-programmierbar-bundle/src/shared/__tests__/invoice-service.test.ts b/...ons/directus-extension-programmierbar-bundle/src/shared/__tests__/invoice-service.test.ts
@@ -5,13 +5,15 @@ import {
     ensureInvoiceDocuments,
     findCancellationFor,
     findCurrentInvoiceDocument,
+    formatServiceDate,
     InvalidTicketCountError,
     issueOriginalInvoice,
     markInvoiceSent,
     MissingDatePaidError,
     negateInvoiceSnapshot,
     parseInvoiceSnapshot,
     renderAndUploadInvoice,
+    withServicePeriod,
     type InvoiceDocument,
     type InvoiceOrder,
     type InvoiceSnapshot,
@@ -159,6 +161,51 @@ describe('buildInvoiceSnapshot', () => {
     })
 })
 
+describe('Leistungsdatum (service date)', () => {
+    const CONFERENCE = { start_on: '2026-11-25T09:00:00', end_on: '2026-11-26T18:00:00' }
+
+    test.each([
+        ['2026-11-25', '2026-11-26', '25.–26.11.2026'],
+        ['2026-11-25T09:00:00', '2026-11-25T18:00:00', '25.11.2026'],
+        ['2026-11-25', null, '25.11.2026'],
+        ['2026-11-30', '2026-12-01', '30.11.–01.12.2026'],
+        ['2026-12-31', '2027-01-01', '31.12.2026–01.01.2027'],
+        [null, null, null],
+    ])('formats %s / %s as %s', (start, end, expected) => {
+        expect(formatServiceDate(start, end)).toBe(expected)
+    })
+
+    test('buildInvoiceSnapshot records the conference dates', () => {
+        const snapshot = buildInvoiceSnapshot(ORDER, 'Conf', 2, CONFERENCE)
+        expect(snapshot.service_date_start).toBe('2026-11-25')
+        expect(snapshot.service_date_end).toBe('2026-11-26')
+    })
+
+    test('withServicePeriod fills older snapshots and keeps recorded dates', () => {
+        const legacy = buildInvoiceSnapshot(ORDER, 'Conf', 2)
+        expect(withServicePeriod(legacy, CONFERENCE)).toMatchObject({
+            service_date_start: '2026-11-25',
+            service_date_end: '2026-11-26',
+        })
+
+        const recorded = buildInvoiceSnapshot(ORDER, 'Conf', 2, { start_on: '2025-11-20', end_on: '2025-11-21' })
+        expect(withServicePeriod(recorded, CONFERENCE)).toBe(recorded)
+    })
+
+    test('renders without a Leistungsdatum (and warns) when no date is known', async () => {
+        const logger = { warn: jest.fn() }
+        const result = await renderAndUploadInvoice({
+            snapshot: buildInvoiceSnapshot(ORDER, 'Conf', 2),
+            invoiceNumber: 'PB-CON26-001',
+            invoiceDate: new Date('2026-02-01T10:00:00Z'),
+            filesService: fakeFilesService(),
+            logger,
+        })
+        expect(result.pdfBuffer.subarray(0, 4).toString()).toBe('%PDF')
+        expect(logger.warn).toHaveBeenCalledWith(expect.stringMatching(/Leistungsdatum.*PB-CON26-001/))
+    })
+})
+
 describe('negateInvoiceSnapshot', () => {
     test('flips every monetary amount and keeps the rest', () => {
         const snapshot = buildInvoiceSnapshot(ORDER, 'Conf', 2)

diff --git a/...s-cms/extensions/directus-extension-programmierbar-bundle/src/shared/invoice-generator.ts b/...s-cms/extensions/directus-extension-programmierbar-bundle/src/shared/invoice-generator.ts
@@ -61,6 +61,11 @@ export type InvoiceDocumentKind = 'invoice' | 'correction' | 'cancellation'
 interface InvoiceDataBase {
     invoiceNumber: string
     invoiceDate: string // formatted DD.MM.YYYY
+    /**
+     * Leistungsdatum (§ 14 Abs. 4 Nr. 6 UStG): the conference date(s), e.g.
+     * "25.–26.11.2026". The line is omitted when no date is known.
+     */
+    serviceDate?: string | null
     // Customer
     purchaserName: string
     purchaserEmail: string
@@ -228,18 +233,24 @@ export function generateInvoicePdf(data: InvoiceData): Promise<Buffer> {
         const metaY = headingWrapped ? Math.ceil(50 + headingHeight + 6) : 75
 
         doc.fontSize(9).fillColor('#666')
-        doc.text(`Rechnungsdatum: ${data.invoiceDate}`, 50, metaY, { align: 'right' })
+        let metaLineY = metaY
+        const metaLine = (text: string) => {
+            doc.text(text, 50, metaLineY, { align: 'right' })
+            metaLineY += 12
+        }
+        metaLine(`Rechnungsdatum: ${data.invoiceDate}`)
+        if (data.serviceDate) {
+            metaLine(`Leistungsdatum: ${data.serviceDate}`)
+        }
         if (kind === 'invoice') {
-            doc.text(`Fälligkeitsdatum: ${data.invoiceDate}`, 50, metaY + 12, { align: 'right' })
+            metaLine(`Fälligkeitsdatum: ${data.invoiceDate}`)
         } else {
             // referenceNumber/referenceDate are guaranteed by the guard above.
-            doc.text(`Bezug: Rechnung Nr. ${data.referenceNumber} vom ${data.referenceDate}`, 50, metaY + 12, {
-                align: 'right',
-            })
+            metaLine(`Bezug: Rechnung Nr. ${data.referenceNumber} vom ${data.referenceDate}`)
         }
 
         // --- Seller info ---
-        let y = Math.max(115, metaY + 40)
+        let y = Math.max(115, metaLineY + 16)
         doc.fontSize(9).fillColor('#333')
         doc.text(SELLER.name, 50, y)
         y += 13