New Year is the time at which a new calendar year begins and the calendar's year count increments by one.
Many cultures celebrate the event in some mannerand the 1st day of January is often marked as a national holiday.
In the Gregorian calendar, the most widely used calendar system today, New Year occurs on 1 January (New Year's Day). This was also the case both in the Roman calendar (at least after about 713 BCE) and in the Julian calendar that succeeded it.
Other calendars have been used historically in different parts of the world; some calendars count years numerically, while others do not.