A Guide to the Hijri Calendar and the Sacred Months

The Hijri calendar counts from the Prophet's migration from Makkah to Madinah, not from his birth. It is lunar, so its year runs about eleven days shorter than the Gregorian one, and its dates move backwards through the seasons.

The Twelve Months

Muharram — one of the four sacred months. Contains Ashura on the tenth. Safar — the month after it. Rabi' al-Awwal — the month of the Prophet's birth and of his arrival in Madinah. Rabi' al-Thani. Jumada al-Ula. Jumada al-Akhirah. Rajab — a sacred month, and the month of the Night Journey. Sha'ban — the month before Ramadan, and the month of preparation for it. Ramadan — the month of fasting, in which the Quran began to be revealed. Shawwal — begins with Eid al-Fitr; the six fasts of Shawwal fall in it. Dhul Qadah — a sacred month. Dhul Hijjah — the month of Hajj, of Arafah and of Eid al-Adha.

The four sacred months are Dhul Qadah, Dhul Hijjah, Muharram and Rajab. The Quran names them, and the reports treat wrongdoing in them as heavier and good deeds in them as greater.

Why the Day Starts at Sunset

A Hijri day begins at Maghrib, not at midnight. The night comes before the day it belongs to.

This is why the night of Eid is the night before the morning of Eid, why Laylatul Qadr is sought on the nights preceding odd days, and why a fast that begins on the twenty-ninth starts the evening before.

Why Dates Shift

A lunar month is the time from one new moon to the next, about 29 and a half days. Twelve of them make roughly 354 days, eleven short of a solar year.

The practical effect is that Ramadan moves through every season across a lifetime. A person born today will fast in winter and in high summer before they are old, which the tradition treats as a fairness: no region and no generation gets only the short fasts or only the long ones.

Why Countries Announce Different Dates

A lunar month begins when the new crescent is sighted. Some countries sight locally; others follow the announcement of Saudi Arabia; others use astronomical calculation.

All three positions are held by scholars, and this is why Eid falls on different days in different countries, sometimes in the same city. Following the position of the body or mosque you normally follow is the ordinary answer, and it is the answer most people take.

Converting Between the Two

There is no simple formula, because the lengths do not divide evenly and because the start of a month depends on sighting. The approximation used most is: Hijri year ≈ (Gregorian year − 622) × 33 ÷ 32.

For anything that matters — a birthday, a memorial, a fast — use a converter rather than the formula, and check it against the calendar your country actually publishes.

The Days Worth Marking

Ashura, the tenth of Muharram — fasting it is recommended, with the ninth alongside it. The white days — the thirteenth, fourteenth and fifteenth of each month, fasted throughout the year. Mondays and Thursdays. The first ten days of Dhul Hijjah, and the Day of Arafah on the ninth. The last ten nights of Ramadan. The six days of Shawwal, after Eid al-Fitr.

Keeping any one of these attaches your year to the calendar in a way that reading about it does not.

Convert a Date

The Hijri converter turns a Gregorian date into a Hijri one and back, and the Islamic calendar shows the month you are in.