Fix invoice issue date shown one day early and inconsistent date format

TRANSLATIONS.md

@@ -1,6 +1,6 @@
 # Translation Status
 
-Last updated: 2026-10-07 09:57:47
+Last updated: 2026-10-09 09:28:47
 
 Reference locale (en): **346 keys**
 

backend/src/controllers/invoices.ts

@@ -1470,9 +1470,9 @@ function applyDerivedOverdue<
   if (!inv.dueDate) return inv;
   const today = new Date();
   const dd = new Date(
-    inv.dueDate.getFullYear(),
-    inv.dueDate.getMonth(),
-    inv.dueDate.getDate(),
+    inv.dueDate.getUTCFullYear(),
+    inv.dueDate.getUTCMonth(),
+    inv.dueDate.getUTCDate(),
   );
   const td = new Date(today.getFullYear(), today.getMonth(), today.getDate());
   if (dd < td) {

backend/src/utils/facturx.ts

@@ -16,9 +16,9 @@ function xmlEscape(v: Maybe<string | number | boolean>): string {
 
 function fmtDateYYYYMMDD(d?: Date): string | undefined {
   if (!d) return undefined;
-  const yyyy = d.getFullYear();
-  const mm = String(d.getMonth() + 1).padStart(2, "0");
-  const dd = String(d.getDate()).padStart(2, "0");
+  const yyyy = d.getUTCFullYear();
+  const mm = String(d.getUTCMonth() + 1).padStart(2, "0");
+  const dd = String(d.getUTCDate()).padStart(2, "0");
   return `${yyyy}${mm}${dd}`;
 }
 

backend/src/utils/fatturapa.ts

@@ -16,9 +16,9 @@ function xmlEscape(v: Maybe<string | number | boolean>): string {
 
 function fmtDate(d?: Date): string | undefined {
   if (!d) return undefined;
-  const yyyy = d.getFullYear();
-  const mm = String(d.getMonth() + 1).padStart(2, "0");
-  const dd = String(d.getDate()).padStart(2, "0");
+  const yyyy = d.getUTCFullYear();
+  const mm = String(d.getUTCMonth() + 1).padStart(2, "0");
+  const dd = String(d.getUTCDate()).padStart(2, "0");
   return `${yyyy}-${mm}-${dd}`;
 }
 

backend/src/utils/pdf.ts

@@ -153,9 +153,11 @@ function lighten(hex: string, amount = 0.85): string {
 function formatDate(d?: Date, format: string = "YYYY-MM-DD") {
   if (!d) return undefined;
   const date = new Date(d);
-  const year = date.getFullYear();
-  const month = String(date.getMonth() + 1).padStart(2, "0");
-  const day = String(date.getDate()).padStart(2, "0");
+  // Issue/due dates are stored as UTC midnight; read UTC parts so the
+  // server's timezone can't shift them by a day.
+  const year = date.getUTCFullYear();
+  const month = String(date.getUTCMonth() + 1).padStart(2, "0");
+  const day = String(date.getUTCDate()).padStart(2, "0");
 
   if (format === "DD.MM.YYYY") {
     return `${day}.${month}.${year}`;

backend/src/utils/ubl.ts

@@ -24,9 +24,9 @@ function xmlEscape(v: Maybe<string | number | boolean>): string {
 
 function fmtDate(d?: Date): string | undefined {
   if (!d) return undefined;
-  const yyyy = d.getFullYear();
-  const mm = String(d.getMonth() + 1).padStart(2, "0");
-  const dd = String(d.getDate()).padStart(2, "0");
+  const yyyy = d.getUTCFullYear();
+  const mm = String(d.getUTCMonth() + 1).padStart(2, "0");
+  const dd = String(d.getUTCDate()).padStart(2, "0");
   return `${yyyy}-${mm}-${dd}`;
 }
 

frontend/src/lib/components/InvoiceEditor.svelte

@@ -18,12 +18,16 @@
   // an explicit override — see the customerId-aware preview effect below).
   let invoiceNumberTouched = $state(false);
 
+  // Today's date in the user's timezone (toISOString() would give the UTC date).
+  const now = new Date();
+  const today = `${now.getFullYear()}-${String(now.getMonth() + 1).padStart(2, "0")}-${String(now.getDate()).padStart(2, "0")}`;
+
   let form = $state({
     customerId: initInvoice?.customerId || "",
     invoiceNumber: initInvoice?.invoiceNumber ?? initNextInvoiceNumber,
     currency: initInvoice?.currency || "EUR",
     status: initInvoice?.status || "draft",
-    issueDate: initInvoice?.issueDate ? new Date(initInvoice.issueDate).toISOString().slice(0, 10) : new Date().toISOString().slice(0, 10),
+    issueDate: initInvoice?.issueDate ? new Date(initInvoice.issueDate).toISOString().slice(0, 10) : today,
     dueDate: initInvoice?.dueDate ? new Date(initInvoice.dueDate).toISOString().slice(0, 10) : "",
     taxMode: initInvoice?.taxMode || "invoice",
     taxRate: initInvoice?.taxRate || 0,

frontend/src/lib/utils/date.test.ts

@@ -0,0 +1,24 @@
+import { describe, expect, test } from "bun:test";
+import { formatDate } from "./date";
+
+describe("formatDate", () => {
+  const utcMidnight = "2026-10-09T00:00:00.000Z";
+
+  test("YYYY-MM-DD", () => {
+    expect(formatDate(utcMidnight, "YYYY-MM-DD")).toBe("2026-10-09");
+  });
+
+  test("DD.MM.YYYY", () => {
+    expect(formatDate(utcMidnight, "DD.MM.YYYY")).toBe("09.10.2026");
+  });
+
+  test("defaults to YYYY-MM-DD", () => {
+    expect(formatDate(new Date(utcMidnight))).toBe("2026-10-09");
+  });
+
+  test("empty and invalid input", () => {
+    expect(formatDate(undefined)).toBe("");
+    expect(formatDate(null)).toBe("");
+    expect(formatDate("not a date")).toBe("");
+  });
+});

frontend/src/lib/utils/date.ts

@@ -0,0 +1,23 @@
+/**
+ * Format a date using the "Date Format" setting (Settings → Localization).
+ *
+ * Invoice issue/due dates are stored as UTC midnight, so by default the UTC
+ * parts are used; otherwise browsers west of UTC would show the previous day.
+ * Pass `utc = false` for real timestamps (e.g. updatedAt) to show local time.
+ */
+export function formatDate(
+  d: string | Date | null | undefined,
+  format: string = "YYYY-MM-DD",
+  utc = true,
+): string {
+  if (!d) return "";
+  const dt = typeof d === "string" ? new Date(d) : d;
+  if (Number.isNaN(dt.getTime())) return "";
+  const year = utc ? dt.getUTCFullYear() : dt.getFullYear();
+  const month = String((utc ? dt.getUTCMonth() : dt.getMonth()) + 1).padStart(2, "0");
+  const day = String(utc ? dt.getUTCDate() : dt.getDate()).padStart(2, "0");
+  if (format === "DD.MM.YYYY") {
+    return `${day}.${month}.${year}`;
+  }
+  return `${year}-${month}-${day}`;
+}

frontend/src/routes/dashboard/+page.svelte

@@ -1,13 +1,14 @@
 <script lang="ts">
   import { ShieldOff } from "lucide-svelte";
   import { getContext } from "svelte";
+  import { formatDate } from "$lib/utils/date";
   import { invoiceStatusLabel } from "$lib/i18n/mod";
 
   let { data } = $props();
 
   let t = getContext("i18n") as (key: string) => string;
   let numberFormat = $derived(data.localization?.numberFormat || "comma");
-  let dateLocale = $derived(data.localization?.locale || "en");
+  let dateFormat = $derived(data.localization?.dateFormat || "YYYY-MM-DD");
   let statusCounts = $derived((data.status || {}) as Record<string, number>);
   let user = $derived(data.user);
   let canViewInvoices = $derived(user?.isAdmin || user?.permissions?.some((p) => p.resource === "invoices" && p.action === "read"));
@@ -225,7 +226,7 @@
             </td>
             <td class="text-right text-sm tabular-nums">
               {#if inv.issueDate}
-                {new Date(inv.issueDate).toLocaleDateString(dateLocale, { year: "numeric", month: "short", day: "numeric" })}
+                {formatDate(inv.issueDate, dateFormat)}
               {/if}
             </td>
           </tr>

frontend/src/routes/invoices/+page.svelte

@@ -1,12 +1,13 @@
 <script lang="ts">
   import { ShieldOff, SquarePen } from "lucide-svelte";
   import { getContext } from "svelte";
+  import { formatDate } from "$lib/utils/date";
 
   let { data } = $props();
 
   let t = getContext("i18n") as (key: string) => string;
   let numberFormat = $derived(data.localization?.numberFormat || "comma");
-  let dateLocale = $derived(data.localization?.locale || "en");
+  let dateFormat = $derived(data.localization?.dateFormat || "YYYY-MM-DD");
   let user = $derived(data.user);
   let canCreate = $derived(user?.isAdmin || user?.permissions?.some((p) => p.resource === "invoices" && p.action === "create"));
   let canViewCustomers = $derived(user?.isAdmin || user?.permissions?.some((p) => p.resource === "customers" && p.action === "read"));
@@ -177,7 +178,7 @@
               <a href={`/invoices/${inv.id}`}>{inv.invoiceNumber}</a>
               <div class="text-xs opacity-70 sm:hidden">
                 {#if inv.issueDate}
-                  {new Date(inv.issueDate).toLocaleDateString(dateLocale, { year: "numeric", month: "short", day: "numeric" })}
+                  {formatDate(inv.issueDate, dateFormat)}
                 {/if}
               </div>
             </td>
@@ -206,7 +207,7 @@
             </td>
             <td class="hidden text-sm tabular-nums sm:table-cell">
               {#if inv.issueDate}
-                {new Date(inv.issueDate).toLocaleDateString(dateLocale, { year: "numeric", month: "short", day: "numeric" })}
+                {formatDate(inv.issueDate, dateFormat)}
               {/if}
             </td>
             {#if showPaidWith}
@@ -216,7 +217,7 @@
             {/if}
             <td class="hidden text-right text-sm tabular-nums opacity-70 md:table-cell">
               {#if inv.updatedAt}
-                {new Date(inv.updatedAt).toLocaleDateString(dateLocale, { year: "numeric", month: "short", day: "numeric" })}
+                {formatDate(inv.updatedAt, dateFormat, false)}
               {/if}
             </td>
           </tr>

frontend/src/routes/invoices/[id]/+page.svelte

@@ -8,6 +8,7 @@
 
   import { hasPermission } from "$lib/types";
   import { formatPostalCityLine } from "$lib/address";
+  import { formatDate } from "$lib/utils/date";
 
   let { data, form } = $props();
   let t = getContext("i18n") as (key: string) => string;
@@ -23,7 +24,7 @@
     const due = invoice.dueDate ? new Date(invoice.dueDate as string) : null;
     if (!due) return false;
     const today = new Date();
-    const dueDateObj = new Date(due.getFullYear(), due.getMonth(), due.getDate());
+    const dueDateObj = new Date(due.getUTCFullYear(), due.getUTCMonth(), due.getUTCDate());
     const todayObj = new Date(today.getFullYear(), today.getMonth(), today.getDate());
     return dueDateObj.valueOf() < todayObj.valueOf();
   });
@@ -61,17 +62,8 @@
     emailDialog?.showModal();
   }
 
-  function fmtDate(d?: string | Date) {
-    if (!d) return "";
-    const dt = typeof d === "string" ? new Date(d) : d;
-    if (Number.isNaN(dt.getTime())) return "";
-    const year = dt.getFullYear();
-    const month = String(dt.getMonth() + 1).padStart(2, "0");
-    const day = String(dt.getDate()).padStart(2, "0");
-    if (getLoc()?.dateFormat === "DD.MM.YYYY") {
-      return `${day}.${month}.${year}`;
-    }
-    return `${year}-${month}-${day}`;
+  function fmtDate(d?: string | Date, utc = true) {
+    return formatDate(d, getLoc()?.dateFormat, utc);
   }
 
   function fmtMoney(v?: number) {
@@ -80,7 +72,7 @@
 
   function fmtDateTime(d: Date) {
     if (!d || Number.isNaN(d.getTime())) return "";
-    const date = fmtDate(d);
+    const date = fmtDate(d, false);
     const h = String(d.getHours()).padStart(2, "0");
     const m = String(d.getMinutes()).padStart(2, "0");
     return `${date} ${h}:${m}`;