The Persian calendar (Solar Hijri, or Shamsi) is the official calendar of Iran and Afghanistan. It is one of the most accurate solar calendars in the world, with the year beginning precisely at the spring equinox (Nowruz). The current year is 1404 SH; year 1405 begins at Nowruz on 21 March 2026.
The first six months have 31 days, the next five have 30 days, and the last month (Esfand) has 29 days (30 in a leap year).
The 12 months are: Farvardin, Ordibehesht, Khordad, Tir, Mordad, Shahrivar, Mehr, Aban, Azar, Dey, Bahman, and Esfand.
The year always begins on the day of the spring (vernal) equinox in Iran, making it astronomically tied to the seasons — unlike the Islamic (lunar) Hijri calendar, which drifts.
Both the Persian (Solar Hijri) and Islamic (Lunar Hijri) calendars count years from the Hijra (622 CE) — but they measure the year differently.
The Solar Hijri year (~365 days) stays fixed to the seasons. The Lunar Hijri year (~354 days) is about 11 days shorter, so its dates move earlier each Gregorian year.
This is why the Persian year number (1404) and the Islamic year number (1447) differ by dozens of years despite the same starting point.