An Etymological Dictionary of Astronomy and Astrophysics

The time interval between the new year’s day in a given calendar system and the day before the following new year’s day. In the Gregorian system the calendar year begins on January 1 and ends on December 31. In the Iranian calendar it begins on Farvardin 1, the day closest to the spring equinox and ends on Esfand 29 or 30.

See also: → calendar; → year.