zeitzone auch fü started und finished angepasst

math-tutor/backend/app/deterministic_services/orchestrators/orchestrator_base.py

@@ -2,7 +2,8 @@ from __future__ import annotations
 
 import time
 from dataclasses import dataclass
-from datetime import datetime, timezone
+from datetime import datetime
+from zoneinfo import ZoneInfo
 from typing import Any, Callable, List, TypeVar
 
 import app.config as config
@@ -39,7 +40,7 @@ def is_new_chat(messages: list[dict]) -> bool:
 # ---
 
 def _utc_now_iso() -> str:
-    return datetime.now(timezone.utc).strftime("%Y-%m-%dT%H:%M:%SZ")
+    return datetime.now(ZoneInfo("Europe/Berlin")).strftime("%Y-%m-%dT%H:%M:%SZ")
 
 
 def _start_timing() -> tuple[str, float]: