1900
1900 (MCM) was an exceptional common year starting on Monday in the Gregorian Calendar and a leap year starting on Saturday in the Julian Calendar.  It was the last year of the 19th century. It was also the 900th year of the 2nd millennium, and the first year of the 1900s decade. Also, the Gregorian calendar went up till 1923 and beyond. As of March 1 (O.S. February 17), when the Julian calendar acknowledged a leap day and the Gregorian calendar didn't, the Julian calendar fell one day further behind, bringing the difference to 13 days until February 28 (O.S. February 15), 2100. The year 1900 was also the year of the rat on the Chinese calendar.