Persian Jalali calendar converter

Solar Hijri, why it's the most accurate calendar still in use

The Iranian Solar Hijri calendar is observational. The new year flips on the spring equinox itself, not on a fixed date, and the leap rule comes from a 33-year intercalation cycle that keeps the average year within about a second of the true tropical year. The Gregorian calendar, by comparison, drifts roughly 27 seconds per year. Over the next few millennia the Iranian calendar will keep step with the seasons; the Gregorian will not.

Nowruz: when the Iranian year actually flips

Nowruz means "new day". It happens at the exact moment of the vernal equinox, and the new year takes whichever calendar day the equinox falls on in Tehran solar time. That is why Nowruz can land on 20 or 21 March depending on the year, for AP 1405, the equinox is late on 20 March UTC but already 21 March in Iran, so 1 Farvardin 1405 is 21 March 2026. Most years it is a one-day window. The converter above resolves the edge case for you.

Iranian vs Afghan year numbers

Iran and Afghanistan both use the Solar Hijri epoch and the same year numbers. The differences are in the month names, Iranian Farvardin is Afghan Hamal, Ordibehesht is Sawr, and so on, mostly drawn from Arabic zodiac roots, and a few civil holidays. Some older Afghan almanacs counted from a slightly different starting year, but the modern civil calendar is in lockstep with Iran. If you see a year number that differs by one, it is almost always a typo or a folk-calendar quirk, not a real disagreement.

Best uses

• Planning Nowruz greetings, dinners, or product launches a year ahead.
• Cross-referencing a Persian date in a document, news article, or family record with its Gregorian equivalent.
• Catching the Yalda window, winter solstice night, when families read Hafez and eat pomegranates.
• Sending a Sizdah Bedar picnic invite without having to count thirteen days into the year by hand.

The engine here is Borkowski's closed-form 1996 algorithm, accurate over AP 1244-1632 (1865-2253 CE). For dates outside that band, an astronomical calculation is needed and the answer can drift by a day either way.