Handle timezones

aleksis/apps/kolego/schema/absence.py

+from datetime import datetime, timezone
+from zoneinfo import ZoneInfo
+
+from django.conf import settings
+
 import graphene
 from graphene_django import DjangoListField
 from graphene_django.types import DjangoObjectType
@@ -45,6 +50,21 @@ class AbsenceCreateMutation(DjangoCreateMutation):
         optional_fields = ("comment", "reason")
         permissions = ("",)  # FIXME
 
+    @classmethod
+    def handle_datetime_start(cls, value, name, info) -> int:
+        value = value.replace(tzinfo=timezone.utc)
+        return value
+
+    @classmethod
+    def handle_datetime_end(cls, value, name, info) -> int:
+        value = value.replace(tzinfo=timezone.utc)
+        return value
+
+    @classmethod
+    def before_save(cls, root, info, input, obj):
+        obj.timezone = ZoneInfo(settings.TIME_ZONE) # FIXME Use TZ provided by client
+        return obj
+
 
 class AbsenceBatchCreateMutation(DjangoBatchCreateMutation):
     class Meta:
@@ -64,6 +84,21 @@ class AbsenceBatchPatchMutation(PermissionBatchPatchMixin, DjangoBatchPatchMutat
         fields = ("id", "person", "reason", "comment", "datetime_start", "datetime_end")
         permissions = ("",)  # FIXME
 
+    @classmethod
+    def handle_datetime_start(cls, value, name, info) -> int:
+        value = value.replace(tzinfo=timezone.utc)
+        return value
+
+    @classmethod
+    def handle_datetime_end(cls, value, name, info) -> int:
+        value = value.replace(tzinfo=timezone.utc)
+        return value
+
+    @classmethod
+    def before_save(cls, root, info, input, obj):
+        obj.timezone = ZoneInfo(settings.TIME_ZONE) # FIXME Use TZ provided by client
+        return obj
+
 
 class AbsenceReasonCreateMutation(DjangoCreateMutation):
     class Meta: