changes to translation system

website/js/datetime.js

@@ -0,0 +1,31 @@
+/** App timezone for display (Germany: CET/CEST). */
+export const APP_TIMEZONE = 'Europe/Berlin';
+
+/** YYYY-MM-DD in app timezone (date inputs, log filters, filename stamps). */
+export function berlinDateInputValue(date = new Date()) {
+    return new Intl.DateTimeFormat('en-CA', { timeZone: APP_TIMEZONE }).format(date);
+}
+
+/** YYYY-MM-DD HH:mm:ss in app timezone. */
+export function formatBerlinDateTime(value) {
+    const d = value instanceof Date ? value : new Date(value);
+    if (Number.isNaN(d.getTime())) return '';
+    const parts = new Intl.DateTimeFormat('en-GB', {
+        timeZone: APP_TIMEZONE,
+        year: 'numeric',
+        month: '2-digit',
+        day: '2-digit',
+        hour: '2-digit',
+        minute: '2-digit',
+        second: '2-digit',
+        hour12: false,
+    }).formatToParts(d);
+    const get = (type) => parts.find((p) => p.type === type)?.value ?? '';
+    return `${get('year')}-${get('month')}-${get('day')} ${get('hour')}:${get('minute')}:${get('second')}`;
+}
+
+/** YYYY-MM-DD HH:mm in app timezone. */
+export function formatBerlinDateTimeShort(value) {
+    const full = formatBerlinDateTime(value);
+    return full ? full.slice(0, 16) : '';
+}