code: public double getGreenwichSidereal() {
          if (siderealTime == INVALID) {
              // See page 86 of "Practial Astronomy with your Calculator",
              // by Peter Duffet-Smith, for details on the algorithm.
  
              double UT = normalize((double)time/HOUR_MS, 24);
  
              siderealTime = normalize(getSiderealOffset() + UT*1.002737909, 24);
          }
          return siderealTime;
      }
docs: Returns the current Greenwich sidereal time, measured in hours
  @hide draft / provisional / internal are hidden on Android