The christian calendar | calendars, What is the roman calendar? before julius caesar introduced the julian calendar in 45 b.c.e., the roman calendar was a mess, and much of our so-called "knowledge. Old style style dates - wikipedia, Old style (o.s.) and new style (n.s.) are terms sometimes used with dates to indicate that the calendar convention used at the time described is different from that. Calendar converter, The islamic calendar is purely lunar and consists of twelve alternating months of 30 and 29 days, with the final 29 day month extended to 30 days during leap years..

From julian gregorian calendar - time date, Change julian gregorian calendar. gregorian calendar introduced 1582, 300 years countries . https://www.timeanddate.com/calendar/julian-gregorian-switch.html Julian date calendar date - united states navy, Julian dates (abbreviated jd) simply continuous count days fractions noon universal time january 1, 4713 bc ( julian calendar). 2.5. http://aa.usno.navy.mil/data/docs/JulianDate.php Julian day - wikipedia, Terminology. term julian date refer, astronomy, day--year number ( properly, ordinal date) gregorian calendar. https://en.wikipedia.org/wiki/Julian_day