What Is the Hijri Calendar?

The Hijri calendar is the Islamic lunar calendar of 12 months and about 354 days, counted from the migration (Hijrah) of the Prophet Muhammad ﷺ to Medina in 622 CE. This guide explains how it works, lists its 12 months, and shows how its dates relate to the Gregorian calendar. It is written for anyone converting dates or planning around Islamic observances.

What is the Hijri calendar?

The Hijri calendar is a lunar calendar of 12 months used across the Muslim world to date religious observances. Its years are counted from 622 CE and marked AH — Anno Hegirae, “in the year of the Hijrah”.

The first Islamic year began with the Hijrah, the Prophet Muhammad’s ﷺ migration from Mecca to Medina. Its starting point, 1 Muharram 1 AH, falls on 16 July 622 CE in the Gregorian calendar. The second Caliph, Umar ibn al-Khattab, formalized the calendar in 638 CE (17 AH) and chose the Hijrah — not a birth or a battle — as its anchor.

Unlike the Gregorian calendar, which is solar and tracks the Earth’s orbit around the Sun, the Hijri calendar tracks the phases of the Moon. That single difference shapes everything below.

How does the Hijri calendar work?

The Hijri calendar follows the Moon. Each of its 12 months begins with the new crescent and lasts 29 or 30 days, giving a year of about 354 days — roughly 11 days shorter than the 365-day solar year.

Each lunar cycle — new moon to new moon — lasts about 29.53 days. Twelve cycles total roughly 354.37 days. The Hijri calendar never adds a leap month to catch up with the seasons, which is what keeps it purely lunar. The lunisolar Hebrew calendar does add one; the Hijri calendar does not.

Because no correction is made, the months drift against the solar year. A month that falls in summer today will fall in spring within about a decade, and return to summer after roughly 33 years.

What are the 12 months of the Hijri calendar?

The 12 Hijri months run from Muharram to Dhu al-Hijjah. Four are sacred (ḥurum) months — Muharram, Rajab, Dhu al-Qiʿdah and Dhu al-Hijjah — in which warfare was traditionally forbidden.

How is the start of each Hijri month determined?

A Hijri month starts when the new crescent moon (hilāl) is first seen after sunset. Two methods decide the date: direct moon-sighting and astronomical calculation, such as Saudi Arabia’s Umm al-Qura calendar.

The Umm al-Qura calendar is the official civil calendar of Saudi Arabia. It is calculated in advance from astronomical data, which lets governments, banks and software print Hijri dates years ahead. MultiCalculators uses Umm al-Qura, matching most major Islamic platforms. The Umm al-Qura calendar guide explains its exact month rule.

Many countries still confirm the first day of a month by local moon-sighting. When the crescent is not visible on the 29th evening, the current month completes 30 days. Because sighting depends on weather and location, the observed start can differ from the calculated start by about one day. No calculated calendar overrides a local religious ruling.

Why does the Hijri calendar move about 11 days earlier each year?

Because the lunar year is about 11 days shorter than the solar year, each Hijri date falls about 11 days earlier in the Gregorian calendar every year. Over roughly 33 years, a date cycles through all four seasons.

This is why Ramadan is not fixed to a season. The first day of Ramadan fell on 18 February 2026 (1 Ramadan 1447 AH) and arrives again near 8 February 2027 (1448 AH) — about 11 days earlier. The same shift applies to every Hijri date, which is why one Gregorian birthday maps to a new Hijri date each year. You can see this pattern on any Hijri date page, which lists the same Gregorian date across several years.

How is the Hijri calendar different from the Gregorian calendar?

The Hijri calendar is lunar; the Gregorian calendar is solar. A Hijri year runs about 354 days against the Gregorian 365, so the two drift apart by roughly 11 days a year and never align permanently.

Both calendars divide the year into 12 months, but they count time for different reasons. The Gregorian calendar keeps dates fixed to the seasons for civil life; the Hijri calendar keeps dates fixed to the Moon for worship. Across the Muslim world the two run side by side — a Gregorian date for work and records, a Hijri date for Ramadan, the Eids and Hajj. Converting between them is therefore an everyday need, not a rare one.

How do you convert Hijri and Gregorian dates?

Convert a date by matching it against a calculated calendar like Umm al-Qura. The simplest method is an online converter: enter a Gregorian date to get the Hijri date, or enter a Hijri date to get the Gregorian one.

Manual conversion is possible but error-prone, because month lengths vary between 29 and 30 days and are not fixed in advance under moon-sighting. A converter removes that uncertainty. For birthdays and milestones, the Islamic age calculator reports your age in Hijri years, months and days. To read the full context for a single day, browse the Hijri date pages.

What are the most important dates in the Hijri calendar?

The key Islamic dates are the Islamic New Year (1 Muharram), Ashura (10 Muharram), Ramadan (month 9), Eid al-Fitr (1 Shawwal), the Day of Arafah (9 Dhu al-Hijjah) and Eid al-Adha (10 Dhu al-Hijjah).

• Islamic New Year — 1 Muharram. The first day of the Hijri year.
• Day of Ashura — 10 Muharram. A day of recommended voluntary fasting.
• Ramadan — month 9. The month of obligatory fasting; its last ten nights contain Laylat al-Qadr.
• Eid al-Fitr — 1 Shawwal. The festival marking the end of Ramadan.
• Day of Arafah — 9 Dhu al-Hijjah. The pinnacle of Hajj and a day of fasting for non-pilgrims.
• Eid al-Adha — 10 Dhu al-Hijjah. The festival of sacrifice during the Hajj.

Frequently asked questions

Is the Hijri calendar the same as the lunar Islamic calendar?

Yes. “Hijri calendar”, “Islamic calendar” and “Muslim lunar calendar” name the same system of 12 lunar months counted from the Hijrah in 622 CE.

What year is it now in the Hijri calendar?

As of October 2026, it is the year 1448 AH. The Hijri year advances about 11 days earlier against the Gregorian calendar each year.

Does the Hijri calendar have leap years?

The tabular (calculated) Islamic calendar adds one leap day in 11 of every 30 years. Moon-sighting calendars instead adjust naturally, as each month runs 29 or 30 days.

Who uses the Hijri calendar today?

Saudi Arabia uses it as an official civil calendar, and Muslims worldwide use it to date Ramadan, the two Eids, Hajj and other religious observances.

What does AH mean, and how is it different from CE?

AH means Anno Hegirae and counts years from the Hijrah in 622 CE. CE (Common Era) is the Gregorian count. 1 AH began in 622 CE.

Which Hijri month is Ramadan?

Ramadan is the ninth month of the Hijri calendar. It is the month of obligatory fasting and the month in which the Quran began to be revealed.

In short, the Hijri calendar is a purely lunar system of 12 months and about 354 days, counted from 622 CE, with four sacred months and a date that shifts about 11 days earlier each Gregorian year. To put it to use, convert a date with the Umm al-Qura converter.

Dates use the Umm al-Qura calculation · local moon-sighting may differ by ±1 day · MultiCalculators.com