Tags: Year.
Year 1900 (MCM) was a common year starting on Monday (link will display the full calendar) of the Gregorian calendar and a leap year starting on Saturday of the Julian calendar. As a result the Julian calendar was 12 days behind the Gregorian until Wednesday February 28 (O.S. February 16) and has been 13 days behind since Thursday March 1 (O.S. February 17).