Solar Hijri vs Lunar Hijri: Two Calendars Explained
Solar Hijri and lunar Hijri share an era associated with the Hijra, but they count years using different cycles. Their year numbers and month boundaries therefore differ.
Babylon Encyclopedia · Published November 2, 2026 · Companion to Babylon Persia ↗
The solar year and the lunar year
Iran’s national Solar Hijri calendar follows the solar year and the seasons, with its new year linked to the March equinox. The Islamic lunar calendar counts twelve lunar months. Its year is shorter than the solar year, so its named months move through the seasons.
In the loaded 1405 edition, the civil year begins on 21 March 2026. Its first row also carries 1 Shawwal 1447 as the published Iranian lunar date. These are two labels for the same civil day.
How they compare
| System | Cycle | What you see in Persia |
|---|---|---|
| Solar Hijri | Solar year | Iran’s national year, month and day |
| Lunar Hijri | Twelve lunar months | Published Iranian religious dates |
| Gregorian | Solar civil calendar | International date for the same day |
Why Ramadan moves through the seasons
Twelve lunar months are roughly ten to eleven days shorter than a solar year. Ramadan consequently begins earlier in the solar calendar in successive years, moving through the seasons over roughly thirty-three solar years.
The name of a lunar month remains in sequence while its seasonal setting changes. A historical month-name association is therefore different from a prediction of the present season.
Why the date authority matters
Babylon Persia transcribes the lunar dates in Iran’s published calendar. It does not replace them with a generic converter or another country’s calendar. Actual religious month-establishment rules and later announcements can require separate checking.
The Moon view shows calculated phase and horizon information next to those published dates. A conjunction calculation, a visible crescent and an officially accepted month start describe related but different things.
Explore this in Babylon Persia.
Choose a day and follow the published calendar, Moon view and prayer-clock explanations.
Compare dates in the full calendar ↗