feat: Add Berlin date-time formatting for match results processing

backend/services/autoFetchMatchResultsService.js

@@ -14,6 +14,32 @@ import { devLog } from '../utils/logger.js';
 import SeasonService from './seasonService.js';
 
 class AutoFetchMatchResultsService {
+  getBerlinDateTimeParts(value) {
+    const formatter = new Intl.DateTimeFormat('en-CA', {
+      timeZone: 'Europe/Berlin',
+      year: 'numeric',
+      month: '2-digit',
+      day: '2-digit',
+      hour: '2-digit',
+      minute: '2-digit',
+      second: '2-digit',
+      hourCycle: 'h23',
+    });
+    const parts = Object.fromEntries(
+      formatter.formatToParts(value)
+        .filter((part) => part.type !== 'literal')
+        .map((part) => [part.type, part.value])
+    );
+    return {
+      year: Number(parts.year),
+      month: Number(parts.month),
+      day: Number(parts.day),
+      hour: parts.hour,
+      minute: parts.minute,
+      second: parts.second,
+    };
+  }
+
   parseMatchDateTime(rawValue) {
     if (!rawValue) {
       return { date: null, time: null };
@@ -23,14 +49,16 @@ class AutoFetchMatchResultsService {
       const normalized = rawValue.trim();
       const hasExplicitTimezone = /(?:Z|[+-]\d{2}:?\d{2})$/i.test(normalized);
 
-      // ISO values with explicit timezone are often UTC timestamps.
-      // Convert them to local clock time before persisting date/time parts.
+      // myTischtennis supplies ISO values with an explicit timezone in UTC.
+      // Match start times are local civil times, therefore never depend on the
+      // server process timezone (production commonly runs in UTC).
       if (hasExplicitTimezone) {
         const zoned = new Date(normalized);
         if (!Number.isNaN(zoned.getTime())) {
+          const berlin = this.getBerlinDateTimeParts(zoned);
           return {
-            date: new Date(zoned.getFullYear(), zoned.getMonth(), zoned.getDate(), 0, 0, 0, 0),
-            time: `${String(zoned.getHours()).padStart(2, '0')}:${String(zoned.getMinutes()).padStart(2, '0')}:${String(zoned.getSeconds()).padStart(2, '0')}`
+            date: new Date(berlin.year, berlin.month - 1, berlin.day, 0, 0, 0, 0),
+            time: `${berlin.hour}:${berlin.minute}:${berlin.second}`
           };
         }
       }