As a Christian feast day: Saint John Cassian

John Cassian, also known as John the Ascetic and John Cassian the Roman, was a Christian monk and theologian celebrated in both the Western and Eastern churches for his mystical writings. Cassian is noted for his role in bringing the ideas and practices of early Christian monasticism to the medieval West.

February 29 is a leap day —an intercalary date added periodically to create leap years in the Julian and Gregorian calendars. It is the 60th day of a leap year in both Julian and Gregorian calendars, and 306 days remain until the end of the leap year. It is the last day of February in leap years only. It is also the last day of meteorological winter in the Northern Hemisphere and the last day of meteorological summer in the Southern Hemisphere in leap years.