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Leap Year in the Iranian Calendar

The Iranian or Persian calendar has about eight leap years in a 33-year cycle. An extra day is added to the last month in a leap year.

Iran flag waving in the wind above skyline of Tehran lit by orange glow of sunset.

Iranian flag over Teheran, Iran.

The Iranian flag flying over Teheran, Iran.


The Iranian or Persian calendar dates back to the 11th century when a panel of scientists created a calendar that was more accurate than other calendars at the time.

Go to Calendar for Iran

More Accurate Than Gregorian

The current version of the Persian calendar is much more precise than the Gregorian calendar used around the world. While the Gregorian calendar is off by one day in about 3236 years, the Iranian calendar only needs a one-day correction about every 110,000 years.

Persian Leap Years

Leap years in the Iranian calendar usually occur every four years. After every six or seven leap years, the Iranian calendar includes a leap year that occurs on the fifth year instead of the fourth year.

Leap Years in the Gregorian calendar

A period of 2820 years was the base for calculations to establish the frequency of a leap year occurring in the fifth year. At the start and end of this 2820-year cycle, the vernal equinox takes place at exactly the same time of the tropical year.

Topics: Leap Year, Calendar


Alternative Leap Years

  1. Bahá'í Leap Year
  2. Chinese Leap Year
  3. The Ethiopian Leap Year
  4. The Hindu Leap Year
  5. The Iranian Leap Year
  6. The Islamic Leap Year
  7. The Jewish or Hebrew Leap Year

Leap Years in Other Calendars

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