The inaugural day of the year in the Gregorian calendar is known as New Year's Day, occurring precisely one week after the preceding year's Christmas Day.

New Year's Day is recognized as a public holiday in all nations following the Gregorian calendar, excluding Israel. Consequently, it stands as the most universally observed public holiday worldwide.

In certain regions, January 2nd may also be designated as an extra day for New Year celebrations.

For countries adhering to the Julian Calendar, New Year's Day is observed on January 14th.