Update GSSHA cards for simulation start

def _update_simulation_start_cards(self):
        """
        Update GSSHA cards for simulation start
        """
        if self.simulation_start is not None:
            self._update_card("START_DATE", self.simulation_start.strftime("%Y %m %d"))
            self._update_card("START_TIME", self.simulation_start.strftime("%H %M"))