year, time required for the earth to complete one orbit about the sun. The solar or tropical year is measured relative to the sun and is equal to 365 days, 5 hr, 48 min, 46 sec of mean solar time (see solar time ). The sidereal year , measured relative to the stars, is longer than the tropical year by about 20 min. The calendar year is used for practical purposes and always contains a whole number of days, the ordinary year being 365 days and the leap year 366 days.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.
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