The Persian Calendar Explained

If a Persian speaker tells you they were born in 1370 or that school starts on the first of Mehr, they are using the Persian calendar. It is a solar calendar, it begins in spring, and it is one of the most accurate calendars in use anywhere.

The idea in brief

The calendar's formal name is the Solar Hijri calendar, in Persian هجری شمسی (hejri-ye shamsi). It is the official calendar of Iran and has long been the everyday calendar of Afghanistan as well.

• Solar. A year is one journey of the earth around the sun, as in the Western calendar, so the months always fall in the same season.
• Starting in spring. The year begins at the March equinox. New Year's Day is Nowruz, on 20 or 21 March.
• Counted from 622. Year 1 is the year of the Prophet Muhammad's migration from Mecca to Medina, the same starting point as the Islamic lunar calendar. Because the Persian calendar counts solar years and the Islamic one counts shorter lunar years, the two have drifted more than forty years apart.

The twelve months

The first six months have 31 days, the next five have 30, and the last has 29, or 30 in a leap year. The names come from ancient Iranian tradition and are older than the calendar itself.

The Western dates can shift by a day from year to year. A pleasant feature of the system is that each season is exactly three months: spring starts on the first of Farvardin, summer on the first of Tir, autumn on the first of Mehr and winter on the first of Dey.

Converting a year

For a quick conversion you need one number.

• From Nowruz (about 21 March) to the end of December: Persian year = Western year − 621.
• From 1 January to Nowruz: Persian year = Western year − 622.

So October 2026 is in the Persian year 1405, and February 2027 is still 1405, because the new year has not yet begun. In the other direction, someone born in the summer of 1370 was born in 1370 + 621 = 1991.

For an exact date, use a converter; every Persian phone calendar has one built in. As a rough guide, a Persian month begins around the 21st of a Western month.

Why it is so accurate

Most calendars follow a fixed rule for leap years. The Persian calendar follows the sky. The new year begins on the day of the actual astronomical equinox, as calculated for Iran's meridian, so the calendar cannot drift away from the seasons. Leap years fall mostly every four years and occasionally after five, as the astronomy requires.

The system goes back to the Jalali calendar, worked out in the eleventh century by a group of astronomers that included the mathematician and poet Omar Khayyam. Its modern form, with the present month lengths, was adopted officially in Iran in 1925.

The days of the week

The week begins on Saturday, and Friday is the weekly day of rest. Five of the day names are simply numbers attached to the word for Saturday.

Writing a date

Dates are written year, month, day, usually with slashes: ۱۴۰۵/۰۷/۱۴ is 14 Mehr 1405, which corresponds to 6 October 2026. The digits themselves are written from left to right even though the text around them runs from right to left.

Three calendars at once

People in Iran live with three calendars. The Solar Hijri calendar is used for everyday life, school, work and national holidays. The Islamic lunar calendar sets the religious holidays, which is why those move about eleven days earlier each solar year. The Western calendar is used for international business and travel. A printed Iranian calendar shows all three on every page.

In Afghanistan the same solar calendar is traditionally used with a different set of month names, taken from the signs of the zodiac: the year begins with Hamal (Aries) instead of Farvardin.

Dates worth knowing

• 1 Farvardin: Nowruz, New Year's Day.
• 13 Farvardin: Sizdah Bedar, the day spent outdoors that ends the New Year holiday.
• 1 Mehr: the first day of the school year.
• 30 Âzar: Yalda night, the longest night of the year.
• The last Tuesday evening of Esfand: Chahârshanbe Suri, the fire festival.

Knowing these few dates, and the trick of subtracting 621, is enough to follow most conversations in which the calendar comes up.