The julian gregorian calendars, The julian calendar, the gregorian reform and its adoption, astronomical year numbering, the julian and the gregorian proleptic calendars, and the accuracy of calendars.. When leap year? leap day? | , When is leap year? find out the next leap day, how to calculate leap years, leap year folklore, and more on almanac.com.. Leap year explained - infoplease, Why do we need leap year? the gregorian calendar, which now serves as the standard calendar for civil use throughout the world, has both common years and leap years..
Leap year years - time date, Is 2016 leap year? leap year 366 days, opposed common year, 365. add leap day – february 29 – years.. http://www.timeanddate.com/date/leapyear.html Julian day - wikipedia, Julian gregorian calendar julian day number. algorithm richards convert julian day number, , date gregorian calendar. https://en.wikipedia.org/wiki/Julian_day The julian calendar - time date, The julian calendar reformed ancient roman calendar consists cycles 365-day years 366-day leap year. introduced named . http://www.timeanddate.com/calendar/julian-calendar.html