December 31st (1421) was a Monday. It's the 365th day of the year (366th in leap years) in the Gregorian calendar. There are 0 days left to the end of the year.
December 31st Holidays in History
» Christian Calendar of saints called Feast Day:
» Pope Sylvester I (Catholic Church)
» December 31 (Eastern Orthodox liturgics)
» Public holidays in Azerbaijan named International Solidarity Day (Azerbaijan)