Fix time zone info

hackertours.py

@@ -4,6 +4,7 @@ Creates a schedule.json from the Hackertours planning Excel.
 import math
 import sys
 from datetime import datetime, timedelta, timezone
+from zoneinfo import ZoneInfo
 
 import pandas
 import pytz
@@ -16,6 +17,8 @@ from voc.schedule import Schedule, Event
 def create_schedule(sheet_file: str, schedule_file: str):
     # global voc.tools.VERSION
     voc.tools.VERSION = "0.0.1"
+    TZNAME = "Europe/Amsterdam"
+    tzinfo = ZoneInfo(TZNAME)
 
     planning_df = pandas.read_excel(sheet_file, sheet_name="Tours")
     description_df = pandas.read_excel(sheet_file, sheet_name="Descriptions")
@@ -27,7 +30,7 @@ def create_schedule(sheet_file: str, schedule_file: str):
             d[k] = description_df[k][index]
         descriptions[d['Name']] = d
 
-    start = datetime(year=2025, month=12, day=26, tzinfo=pytz.timezone('Europe/Berlin'))
+    start = datetime(year=2025, month=12, day=26, tzinfo=tzinfo)
     acronym = "ht"
     duration = 4
 
@@ -38,7 +41,7 @@ def create_schedule(sheet_file: str, schedule_file: str):
         month=12,
         day=26,
         days_count=5,
-        tz="Europe/Berlin")
+        tz=TZNAME)
     # schedule.schedule().version = '1.0'
     schedule["conference"]["rooms"] = [{
         "name": "Hackertours",