"අධික අවුරුද්ද" හි සංශෝධන අතර වෙනස්කම්
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==ග්රෙගරි දින දසුන==
However, some exceptions to this rule are required since the duration of a solar year is slightly ''less'' than 365.25 days. Years that are evenly divisible by 100 are ''not'' leap years, unless they are also evenly divisible by 400, in which case they ''are'' leap years.<ref name="rog">[http://www.nmm.ac.uk/server/show/conWebDoc.349 Royal Observatory, Greenwich: Leap years]</ref><ref name="usno"> [http://aa.usno.navy.mil/faq/docs/leap_years.php USNO (U.S. Naval Observatory): Leap Years]</ref> For example, 1600 and 2000 were leap years, but 1700, 1800 and 1900 were not. Similarly, 2100, 2200, 2300, 2500, 2600, 2700, 2900, and 3000 will not be leap years, but 2400 and 2800 will be. By this rule, the average number of days per year will be 365 + 1/4 − 1/100 + 1/400 = 365.2425, which is 365 days, 5 hours, 49 minutes, and 12 seconds. The Gregorian calendar was designed to keep the [[vernal equinox]] on or close to March 21, so that the date of [[Easter]] (celebrated on the Sunday after the 14th day of the Moon—i.e. a [[full moon]]—that falls on or after March 21) remains correct with respect to the vernal equinox.<ref>E.G. Richards, ''Mapping time: The calendar and its history'', p. 240, ISBN 0-19-282065-7</ref> The vernal equinox year is about 365.242374 days long (and increasing).
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