Friday was Christmas day, recognised worldwide as the day of the Gregorian calendar which Christians celebrate the birth of Prophet Isa saws. I have deliberately avoided stating that it is recognised as Isa saws birthday because many Christians have acknowledged that it is not in fact the date of his birth.
Friday was yawmul jummah, and the 13th of rabbi ul awal, the fourth month in the islamic calendar. The 12th of rabbi ul awal is generally recognised as the birth date of the Prophet Muhammad saws. Some Muslims celebrate the milad (or meelad) un Nabi, others do not.