code: def db_value(self, value):
          
          if isinstance(value, pendulum.Pendulum):
              value = datetime.datetime(
                  value.year, value.month, value.day, value.hour, value.minute,
                  value.second, value.microsecond, value.tzinfo
              )
  
          return super(PendulumDateTimeField, self).db_value(value)
docs: Convert the Pendulum instance to a datetime for saving in the db.