Year 1400 (MCD) was a leap year starting on Thursday of the Julian calendar. The year 1400 was not a leap year in the Proleptic Gregorian calendar, it was a common year starting on Wednesday. The leap year began on a Thursday, and it ended on a Friday. The common year began on a Wednesday, and ended on a Wednesday, but the leap year ran from the Thursday to the Friday. The Wednesday at the beginning is January 1, the Wednesday at the end is December 31. It was the last year of the 14th century and the first year of the 15th century.