fix(time-entries): use server time for running timers

apps/time_entries/api/serializers.py

@@ -93,7 +93,7 @@ class TimeEntryCreateSerializer(serializers.Serializer):
     """
     workspace_id = serializers.UUIDField()
     project_id = serializers.UUIDField(required=False, allow_null=True)
-    start_time = serializers.DateTimeField()
+    start_time = serializers.DateTimeField(required=False)
     end_time = serializers.DateTimeField(required=False, allow_null=True)
     description = serializers.CharField(required=False, allow_blank=True, default="")
     tags = serializers.ListField(child=serializers.UUIDField(), required=False)
@@ -102,6 +102,12 @@ class TimeEntryCreateSerializer(serializers.Serializer):
     def validate(self, attrs):
         user = self.context.get("request").user if self.context.get("request") else None
         workspace_id = attrs.get("workspace_id")
+        start_time = attrs.get("start_time")
+        end_time = attrs.get("end_time")
+
+        if end_time is not None and start_time is None:
+            raise serializers.ValidationError({"start_time": "Start time is required when end time is provided."})
+
         project_id = attrs.pop("project_id", serializers.empty)
         if project_id is not serializers.empty:
             if project_id is None: