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
Leap year - October and mid - November. Buddhist calendars in several related forms (each a simplified version of the Hindu calendar) are used on mainland Southeast Asia in the countries of Cambodia, Laos, Thailand, Myanmar (formerly Burma) and Sri Lanka. The Hindu Calendar also known as Vikram Samvat is used in Nepal as the national calendar. All the official work is done based on this calendar. The calendar followed in some parts of South India (mainly in Tamil Nadu) is solar. It has a leap year every four years. The Bahá'í calendar is a solar calendar composed of 19 months of