Methodology & Epoch
The Shahanshahi calendar is Iran's solar calendar, counted from the coronation of Cyrus the Great in 559 BC. The current year is 2585.
Conversion formula
Shahanshahi year = Shamsi (Jalali) year + 1180Shahanshahi year = Gregorian year + 559 (Nowruz → 31 Dec)Shahanshahi year = Gregorian year + 558 (1 Jan → Nowruz)Example: this year is Shamsi 1405; 1405 + 1180 = 2585 Shahanshahi. The day and month never change — only the year number is larger, by 1180.
Convert any date in the converter →Epoch: the coronation of Cyrus the Great (559 BC)
Year 1 of the Shahanshahi calendar is 559 BC, the year Cyrus II founded the Achaemenid Empire. This epoch restores the 1180 years that the Hijri epoch removed from Iran's continuous timeline. The Shahanshahi calendar was Iran's official calendar from 2535 to 2537 (1355–1357 Shamsi / 1976–1978 CE); birth certificates and documents from those years carry Shahanshahi dates.
Accuracy & algorithm
The days, months, week structure and leap-year rule of the Shahanshahi calendar are identical to the Jalali (Shamsi) calendar — one of the most accurate solar calendars in the world. The year begins at the astronomical spring equinox. This site's computations use the standard Jalali algorithm (jalaali-js), and the equinox moments are astronomically calculated.
Sources
- · The Cyrus Cylinder, British Museum, no. ANE 90920
- · The Cambridge History of Iran
- · Precedent: the Shahanshahi calendar as Iran's official calendar, 2535–2537
When citing: "Shahanshahi Calendar (gahshomari.com)". Today is 2585 Shahanshahi, 2026 CE.