Persian Calendar Converter
Convert a Gregorian date to the Persian (Solar Hijri, Shamsi) calendar used in Iran and Afghanistan, and back, from 1925 to 2123.
Result
Persian date: 12 Mehr 1405 SH
Matches the official calendar from its adoption in 1304 (1925) to the end of 1501 (2123); the arithmetic rule first differs from the equinox in 1502.
- Day of the week
- Sunday
- Persian year
- 1405 is a common year: Esfand has 29 days
https://calcgallery.com/date-time/persian-calendar-converter-calculator/
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How to use the Persian Calendar Converter
- Choose whether you are converting a Gregorian date to the Persian calendar or a Persian date to Gregorian.
- For a Persian date, enter the year (for example 1405), pick the month and enter the day.
- Read the converted date, its weekday, and whether that Persian year has a 29 or 30 day Esfand.
- The page answers for 1304 to 1501 (March 1925 to March 2123). Outside that span it says so rather than guess.
Months and leap years
The Persian calendar has twelve months tied to the sun, so each month falls in the same season every year. Mehr always starts in late September and Dey in late December.
Farvardin to Shahrivar 31 days eachMehr to Bahman 30 days eachEsfand 29 days, 30 in a leap yearleap year (25 × year + 11) mod 33 < 8The leap rule gives 8 leap years in every 33, mostly four years apart with one five-year gap in each cycle. Across 33 years that averages 365.2424 days, close to the length of the year from one March equinox to the next.
How the page converts
The page counts the days from a fixed starting point to 1 Farvardin of the year, using the leap rule, and then adds the months before the one you picked. Going the other way, it works out which year a day falls in from the average year length, then which month from the count of days since Nowruz. The weekday comes from the same day count.
The official calendar is astronomical, so the page only answers where the arithmetic rule and the equinox agree. That is every year from the calendar’s adoption in 1304 to 1501.
With your numbers
- Farvardin to Shahrivar have 31 days, Mehr to Bahman 30, and Esfand 29, or 30 in a leap year
- A year is a leap year when (25 × year + 11) leaves a remainder below 8 on division by 33
Quick reference
Matches the official calendar from its adoption in 1304 (1925) to the end of 1501 (2123); the arithmetic rule first differs from the equinox in 1502.
| Example | Result |
|---|---|
| 4 October 2026 | Persian date: 12 Mehr 1405 SH |
| Nowruz 1406 | Gregorian date: March 21, 2027 |
| 13 Farvardin 1406 (Sizdah Bedar) | Gregorian date: April 2, 2027 |
| 30 Esfand 1403 (leap day) | Gregorian date: March 20, 2025 |
| 30 Azar 1405 (Yalda night) | Gregorian date: December 21, 2026 |
| 1 January 2027 | Persian date: 11 Dey 1405 SH |
Common questions about the Persian Calendar Converter
- What is the Persian calendar called?
- Officially the Solar Hijri calendar. In Iran it is often called Shamsi or Jalali, and Afghanistan uses the same reckoning with Dari or Pashto month names. Years are counted from the Hijra in 622, like the lunar Hijri calendar, but they are solar years, so the two calendars give different year numbers.
- When does the Persian year start?
- On Nowruz, the day of the March equinox. If the equinox falls before noon Iran time the year starts that day, otherwise the next day. That is why Nowruz is on 20 or 21 March, and occasionally 19 or 22 March over long periods.
- Why are the first six months longer?
- The calendar follows the sun's yearly path. Farvardin to Shahrivar have 31 days, Mehr to Bahman have 30, and Esfand has 29, or 30 in a leap year. That puts 186 days between the March and September equinoxes, which matches the longer northern summer half of the year.
- Is the arithmetic leap rule exact?
- For the span this page covers, yes. The rule puts 8 leap years in every 33. Iran's official calendar uses the actual equinox, and a test of the rule against that astronomical calendar from 1178 to 3000 found its first exception in 1502. So the page stops at the end of 1501.
- Why does the page start in 1304?
- The Iranian parliament adopted the Solar Hijri calendar with its present month names in 1304 (1925). Dates before that were usually written in the lunar Hijri calendar, so a converted earlier date would not match the documents of the time.