Persian (Solar Hijri) Calendar Converter

About this calculator

This converter translates any date between the Persian calendar — also called the Solar Hijri, Jalali, or Shamsi calendar — and the Gregorian calendar, in either direction. Unlike the lunar Hijri calendar, the Persian calendar is solar: its year is tied to the astronomical northern vernal equinox observed at the Iran standard meridian, so its new year, Nowruz, always lands on 1 Farvardin around 20–21 March, and the calendar never drifts against the seasons. Its twelve months run Farvardin, Ordibehesht, Khordad, Tir, Mordad, Shahrivar, Mehr, Aban, Azar, Dey, Bahman, and Esfand — the first six have 31 days, the next five have 30, and Esfand has 29 (30 in a leap year). Because it counts years from the same 622 CE Hijra as the lunar Hijri calendar but measures solar years, the Persian year number sits about 621–622 below the Gregorian year, so 1403 corresponds to 2024. Pick a direction, type a year, month, and day, and read the converted date with its day of the week. By default it shows today’s Gregorian date converted to the Persian (Shamsi) calendar.

How to read your results

The toggle at the top chooses the direction: "Gregorian → Persian" turns a civil date into its Solar Hijri (Shamsi) equivalent, and "Persian → Gregorian" does the reverse. The headline result is the converted date — its year, named month (Farvardin through Esfand on the Persian side), and day — followed by the day of the week, which is the same real weekday for both calendars because they describe the same 24-hour civil day. Persian years carry no AD/BC split; the count starts from the same 622 CE Hijra as the lunar Hijri calendar, but because it is measured in solar years it is written SH (Solar Hijri, and also AP / Hijri Shamsi) to set it apart from the lunar AH — so a year such as 1403 SH stays put against the seasons instead of sliding earlier each year, and never matches the lunar Hijri year number for the same day. The note under the result explains the solar-versus-lunar distinction and the one rare edge case: this tool uses the standard astronomical equinox rule, which can differ by a day from a printed Iranian almanac only in a borderline equinox year.

How it's calculated

Both directions pivot on the Julian Day Number (JDN), a continuous integer count of days that is independent of any calendar. To convert, the input date is first reduced to its JDN, then that JDN is read out in the target calendar. The Gregorian side uses the standard civil-date formula. The Persian side uses the astronomical Solar Hijri calendar exposed by the platform's ICU library (the `persian` calendar): the year begins at the midnight nearest the instant of the northern vernal equinox computed for the Iran standard meridian (52.5°E), so 1 Farvardin coincides with the equinox and leap years are derived from the equinox itself — an irregular pattern averaging about 8 leap years per 33-year cycle. The day of the week is derived directly from the JDN, so it is identical for both calendars. The first six months hold 31 days, the next five hold 30, and Esfand holds 29 or 30, summing to 365 or 366 days. Anchor: 1 Farvardin 1403 = JDN 2460389.5 = 20 March 2024 CE (Nowruz). "Today" is computed at local civil midnight in your time zone after the page loads, so the default date is correct wherever you are without baking a build-time date into the page.

Worked example

Convert 1 Farvardin 1403 (Persian → Gregorian).

Nowruz — 1 Farvardin 1403 SH, the Solar Hijri New Year — falls on Wednesday, 20 March 2024 CE, the day of the northern vernal equinox. Converting the other way, the autumn marker 1 Mehr 1402 comes out as 23 September 2023. Notice that both Persian dates map to the same point in the seasons every year: Farvardin always opens spring and Mehr always opens autumn, because the Solar Hijri calendar is locked to the equinox rather than to the moon.

Frequently asked questions

What is the difference between the Persian (Solar Hijri) and the lunar Hijri calendar?

They share the same starting era — both count years from the 622 CE Hijra — but they measure time differently. The Persian Solar Hijri (Jalali / Shamsi) calendar is solar: its year follows the sun and the vernal equinox, so it is about 365 days long and stays fixed against the seasons. The lunar Hijri calendar follows the moon, so its year is about 354 days and its dates slide roughly 11 days earlier each Gregorian year. That is why a Persian date such as Nowruz does NOT shift 11 days a year, while Ramadan on the lunar calendar does.

When is Nowruz (Persian New Year)?

Nowruz is 1 Farvardin, the first day of the Persian year, and it falls on the day of the northern vernal (spring) equinox as observed at the Iran standard meridian — around 20 or 21 March on the Gregorian calendar. Because the year is pinned to the equinox, Nowruz never drifts: 1 Farvardin 1403, for instance, fell on 20 March 2024.

How does the 33-year leap cycle work, and how long is the Persian year?

A common Persian year has 365 days and a leap year has 366; the extra day is added to Esfand, the twelfth month, which goes from 29 to 30 days. Leap years are not on a simple every-4-years rule — the Solar Hijri calendar is one of the most astronomically accurate calendars in use, with an irregular pattern that works out to roughly 8 leap years in every 33-year cycle, keeping the calendar aligned to the true equinox far better than the Gregorian rule. This tool follows the astronomical (ICU) determination, so leap years are computed from the equinox itself rather than a fixed arithmetic table.

Why is the Persian year number about 621–622 less than the Gregorian year?

Both the Persian and the lunar Hijri calendars count from the Hijra in 622 CE, but the Persian calendar counts solar years of about 365 days. So the gap between the two year numbers stays roughly constant at 621–622 (for example 1403 ≈ 2024) instead of widening over time the way the lunar Hijri year number does as it gains an extra year about every 33 solar years.

Is this calendar used outside Iran?

Yes. The Solar Hijri calendar is the official civil calendar of Iran and is also used in Afghanistan, where the same twelve solar months are traditionally referred to by zodiac (astrological-sign) names rather than the Persian month names. The underlying astronomy — the equinox-pinned year and Nowruz — is identical in both countries.

Sources

• en.wikipedia.org/wiki/Solar_Hijri_calendar
• www.fourmilab.ch/documents/calendar

Reviewed by the YouCalc Team · Last reviewedJune 13, 2026