Has the New Year always been January 1?

January 1 was not always the date of the first day of a new calendar year, and at a certain point in time, the month of January did not even exist. Even today, cultures that use different calendars than the standard Gregorian calendar have New Year celebrations on days other than January 1, though in most places, January 1 is the official start of a new year.

For example, the Jewish calendar, which is older than the Gregorian calendar, celebrates its new year on a holiday called Rosh Hashana, which falls on a different day every year. The worldwide celebration of a new year on a single day is a relatively new phenomenon.