Intercalation (timekeeping) year of 365 days, an extra day ("leap day" or "intercalary day") about every four years, causing a leap year to have 366 days (Julian, Gregorian and Indian national calendars). The Decree of Canopus, which was issued by the pharaoh Ptolemy III Euergetes of Ancient Egypt in 239 BCE, decreed a solar leap day system; an Egyptian leap year was not adopted until 25 BC, when the Roman Emperor Augustus successfully instituted a reformed Alexandrian calendar. In the Julian calendar, as well as in the Gregorian calendar, which improved upon it, intercalation is done by adding an extra day to
Aztec New Year 22nd. This 365-day calendar was corresponded with the solar year, was divided into 18 'months' of 20 days each, plus 5 'nameless' days at the end of the year. Also, there are some codices that show the existence of the leap year. Aztec New Year The Aztec New Year ( or "Año Nuevo Azteca"; , ) is the celebration of the new year according to the Aztec calendar. The date on which the holiday falls in the Gregorian calendar depends on the version of the calendar used, but it is generally considered to occur at sunrise on March 12. The