code: def to_utc_datetime(self, value):
          
          value = self.to_naive_datetime(value)
  
          if timezone.is_naive(value):
              value = timezone.make_aware(value, timezone.utc)
          else:
              value = timezone.localtime(value, timezone.utc)
          return value
docs: from value to datetime with tzinfo format (datetime.datetime instance)