This page will calculate when the Equinoxes and Solstices are for a given year. Type in a year or use the buttons to step forward and backward year-by-year:
Also see our Moon Phase Calculator
TIME ACCURACY: The calculated times are in Terrestrial Dynamical Time (TDT or TT), a replacement for Ephemeris Times (ET). Meeus claims the error is less than one minute for the years 1951-2050 for these calculations (the errors increase as you move farther away from these dates).
CIVIL TIME: TDT is a uniform time used for astronomical calculations. Civil time, such as UTC (popularly known as GMT, but technically incorrect) or your local time, is corrected for the non-linear changes in the rotation of the earth. This is done accurately only through observations. This web page corrects the the calculated TDT to civil time using a table of observations from 1620 thru 2002. Time corrections outside this range are estimated from predictive equations. See Meeus' book for additional details.
CAUTION: While the output has been spot checked for correctness against known tables, the code has not been thoroughly tested and could contain errors. The underlying algorithms are not exact and times could vary by several minutes. Consult the book credited above for detailed information. Note also that the day-of-week will not be correct when the date is in the Julian calendar (earlier than 1582-Oct-15).