2012 Calendar

The Gregorian year begins on January 1 and ends on December 31 with a length of 365 days in an ordinary year and 366 days in a leap year giving an average length of 365.2425 days. This is very close to the average length of 76 Islamic calendar years (based on the average time between successive vernal equinoxes, currently 365.2424 days and increasing marginally). Other formula-based calendars can have lengths which are further out of step with the solar cycle, for example, the Julian calendar has an average length of 365.25 days, and the Hebrew calendar has an average length of 365.2468 days.