Fait mathématique: 1485 is the number of 3-colored rooted trees with 5 vertices.
Culture générale: 1485 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Date historique: January 24th is the day in 1918 that the Gregorian calendar is introduced in Russia by decree of the Council of People's Commissars effective February 14(NS).