Calendar year
From Wikipedia, the free encyclopedia
According to the Gregorian calendar, the calendar year begins on January 1 and ends on December 31. Other alignments of the 12-month period can be used for purposes of accounting (see fiscal year).
Generally speaking, a calendar year begins on the New Year's day of the given calendar system and ends on the day before the following New Year's day.
By convention, a calendar year consists of a natural number of days. To reconcile the calendar year with an astronomical cycle (which could not possibly be reckoned in a whole number of days), certain years contain extra days. Through further insertion of non-day units of time, the calendar year can be further synchronized; however, these extra units of time are not considered part of the calendar.
