code: def _calculate_solar_time(self, hour, eq_of_time, is_solar_time):
          
          if is_solar_time:
              return hour
  
          return (
              (hour * 60 + eq_of_time + 4 * math.degrees(self._longitude) -
               60 * self.time_zone) % 1440) / 60
docs: Calculate Solar time for an hour.