SiderealTime

SiderealTime[] gives the right ascension of the local meridian for the current date and location.

SiderealTime[date] gives the right ascension of the local meridian for the specified date.

SiderealTime[loc] gives the right ascension of the local meridian for the specified location.

SiderealTime[loc,date] gives the right ascension of the local meridian for the specified date and location.

SiderealTime[{{loc1,date1},{loc2,date2},…}] gives the right ascensions of the local meridians for all specified locations on the specified dates.

SiderealTime[loc,date,func] uses func to determine what to return for extended locations.

SiderealTime["MeanTime",loc,date,func] gives the mean sidereal time for the specified date, location and aggregation function.

Examples

Get the current sidereal time:

SiderealTime[]

Get sidereal time for a specific location:

SiderealTime[Entity["City", {"London", "GreaterLondon", "UnitedKingdom"}]]

Please visit the official Wolfram Language Reference for more details.