code: def datetime2sidereal(time: datetime,
                        lon_radians: float,
                        usevallado: bool = True) -> float:
      
      usevallado = usevallado or Time is None
      if usevallado:
          jd = juliandate(str2dt(time))
  # %% Greenwich Sidereal time RADIANS
          gst = julian2sidereal(jd)
  # %% Algorithm 15 p. 188 rotate GST to LOCAL SIDEREAL TIME
          tsr = gst + lon_radians
      else:
          tsr = Time(time).sidereal_time(kind='apparent',
                                         longitude=Longitude(lon_radians, unit=u.radian)).radian
  
      return tsr
docs: Convert ``datetime`` to sidereal time
  
      from D. Vallado "Fundamentals of Astrodynamics and Applications"
  
  
      time : datetime.datetime
          time to convert
      lon_radians : float
          longitude (radians)
      usevallado : bool, optional
          use vallado instead of AstroPy (default is Vallado)
  
      Results
      -------
  
      tsr : float
          Sidereal time