Anti-sidereal_time
Anti-sidereal time
Artificial time standard
Anti-sidereal time and extended-sidereal time are artificial time standards used to analyze the daily variation in the number of cosmic rays received on Earth. Anti-sidereal time has about 364.25 days per year, one day less than the number of days in a year of solar time, 365.25. Thus each anti-sidereal day is longer than a solar day (24 hr) by about four minutes or 24 hr 4 min. Extended-sidereal time has about 367.25 days per year, one day more than the number of days in a year of sidereal time, 366.25. Thus each extended-sidereal day is shorter than a sidereal day (23 hr 56 min) by about four minutes or 23 hr 52 min. All years mentioned have the same length.[1]