The Zoroastrian calendar has a year that is 365 days long, composed of 12 months of 30 days each, plus an additional period of 5 days at the end of the year. There are three versions of this calendar with different starting dates for the year. The Qadimi ("Ancient") calendar is used in Iran. The Shahanshahi (Shenshai) ('Emperial") calendar is used by the Parsees in India, and is exactly one month (30 days) behind the Shahanshahi calendar. The newer Fasli ("seasonal") calendar is a solar calendar that has leap years that are 366 days long, and always starts the year at the vernal equinox. The leap years in the Fasli calendar occur in the same years as they do in the Gregorian calendar.
Other names used for this calendar are Yazdgirdi or Yazdagirdi named after the last Sassanid king of Yazdegerd III of Persia.
See also: calendars, Zoroastrianism