#leap_day__bissextile_day__February_29  the name of the day that is added during a leap year
  supertype:  particular_day__day  a day assigned to a particular purpose or observance; "Mother's Day"
  part of:  February__Feb  the month following January and preceding March
     part of:  Gregorian_calendar__New_Style  the solar calendar now in general use, introduced by Pope Gregory XIII in 1582 AD to correct an error in the Julian calendar by suppressing 10 days, making Oct 5 be called Oct 15, and providing that only centenary years divisible by 400 should be leap years; it was adopted by Great Britain and the American colonies in 1752
     part of:  winter__wintertime  the coldest season of the year

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