Four Popular Calendars

Solar				Lunar
Julian		Gregorian (modern)		Hebrew		Muslim
Month Names	days	Month Names	days	Month Names	days	Month Names	days
January	31	January	31	Tishri	30	Muharram	30
February	28+1	February	28+1	Heshvan	29-30	Safar	29
March	31	March	31	Kislev	29	Rabi I	30
April	30	April	30	Tevet	29-30	Rabi II	29
May	31	May	31	Shevat	30	Jumada I	30
June	30	June	30	Adar	29-30	Jumada II	29
July	31	July	31	Nisan	30	Rajab	30
August	31	August	31	Iyar	29	Sha'ban	29
September	30	September	30	Sivan	30	Ramadan	30
October	31	October	31	Tammuz	29	Shawwal	29
November	30	November	30	Av	30	Dhu al-Qa'dah	30
December	31	December	31	Elul	29	Dhu al Hijjah	29-30
Total Days	365.25	365.242193			354-355		354-355

• General
  • x + 1 (means month length increases during specified calendar's leap year)
  • x - y (means that month length is periodically changed for lunar alignment)
• Julian (named after Julius Caesar)
  • solar calendar
  • 365.25 days long (yes, the Romans had leap years every four years)
• Gregorian (named after Pope Gregory)
  • solar calendar
  • 365.242193 days long, not 365.25 days as most people think.
• Hebrew
  • lunar calendar
  • year 5743 coincided with September 18, 1982 through August 10, 1983.
• Muslim
  • lunar calendar
  • year 1396, Muharram coincided corresponded with January 1976.