+A leap year adds an extra day, often [February](/wiki/february) 29, to the [calendar](/wiki/calendar) to align human timekeeping with the [Earth's orbit](/wiki/earth_orbit) around the sun. This crucial adjustment, occurring roughly every four [years](/wiki/year), prevents a gradual drift of seasons.
+## See also
+- [Time](/wiki/time)
+- [Date](/wiki/date)
+- [Season](/wiki/season)
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