Leap year
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A leap year is a calendar year that contains an additional day compared to a common year. The 366th day is added to keep the calendar year synchronised with the astronomical year or seasonal year. Sin
1800 calendar, showing that February had only 28 days
A Swedish pocket calendar from 2008 showing 29 February
February 1900 calendar showing that 1900 was not a leap year
In the older Roman Missal, feast days falling on or after 24 February are celebrated one day later in a leap year.
Lunisolar calendar
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A lunisolar calendar is a calendar that combines monthly lunar cycles with the solar year. As with all calendars which divide the year into months, there is an additional requirement that the year hav
Leap year
…A leap year (also known as an intercalary year or bissextile year) is a calendar year that contains an additional day (or, in the case of a lunisolar calendar, a month) compared to a common year. The 366th day (or 13th month) is added to keep the calendar year synchronised with the astronomical year or seasonal…
A page from the Hindu calendar 1871–72
Record of the Chinese calendar for 1834, 1835, and 1836 during the Qing dynasty under the Daoguang Emperor's Reign (道光十四年，道光十五年，道光十六年)
Full Moon 2010