Answer: leapyears

AnswerCrossword Clue
LEAPYEARSWhen US presidents are almost always elected
LEAPYEARSThey contain an extra day
LEAPYEARS2000 and 2004
LEAPYEARSPeriodic synchronizations
LEAPYEARSQuadrennial events
LEAPYEARSWhen Presidential elections take place.
LEAPYEARSThirteen since 1900.
LEAPYEARSCalendar phenomena.
LEAPYEARS1940, 1980, etc.
LEAPYEARSWhen U.S. Presidents are elected
LEAPYEARS2004 and 2008