leap year Synonyms

366 days intercalary year bissextile year bissextile defective year 360 days astronomical year calendar month diamond jubilee quincentenary tercentennial annum bissextile day calendar year abundant year sidereal year bissext duty cycle golden wedding anniversary lunar year bicentenary biennial centenary centennial century commemoration day decennary decennial decennium leap lunation octennial quadrennial quinquennium septennial twelvemonth common year except leap year