Tags: Year.
Year 1800 (MDCCC) was an exceptional common year starting on Wednesday (link will display the full calendar) of the Gregorian calendar and a leap year starting on Sunday of the Julian calendar. The Gregorian calendar was 11 days ahead of the Julian calendar until Friday February 28 [O.S. February 17 1800] 1800 but 12 days ahead from Saturday March 1 [O.S. February 18 1800] 1800.