leap year

leap year

a calendar year of 366 days, February 29 (leap day) being the additional day, that occurs every four years (those whose number is divisible by four) except for century years whose number is not divisible by 400. It offsets the difference between the length of the solar year (365.2422 days) and the calendar year of 365 days

Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

leap year

A year that contains one more day than the usual calendar year so that the average length of the year is brought closer to the tropical year of 365.2422 days or to the lunar year. In the Julian calendar a leap year of 366 days occurred once every four years when the year was divisible by four. In the Gregorian calendar this rule was modified so that century years are leap years only when they are divisible by 400. The additional day is now added at the end of February (Feb. 29).

Collins Dictionary of Astronomy © Market House Books Ltd, 2006

leap year

[′lēp ‚yir]

(astronomy)

A year with 366, and not 365, days.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.