The Hijra of 622: The Journey Behind the Islamic Calendar

The Hijra (also spelled Hijrah or Hegira) is the migration of the Prophet Muhammad ﷺ from Makkah to Yathrib, later called Madinah, in 622 CE. The Companions chose it as the starting point of the Islamic calendar, so the year in which it happened is year 1 AH ("in the year of the Hijra"). The journey itself is traditionally dated to Rabi al-Awwal, the third month. Year 1 begins two months earlier, on 1 Muharram, which corresponds to 16 July 622 in the Julian calendar. That gap, and the uncertainty in converting 7th-century Arabian dates, is why sources give different dates for the Hijra.

Key Takeaways

• The Hijra was the Prophet's migration from Makkah to Madinah in 622 CE, made with Abu Bakr after a three-night stay in the cave of Thawr.
• The Companions counted the calendar from the arrival in Madinah, not from the start of revelation or the Prophet's death.
• The era was introduced by the caliph Umar in 639 CE, with year 1 starting on 1 Muharram (16 July 622, Julian).
• The journey is traditionally placed in Rabi al-Awwal, so the commonly cited "September 622" is a back-calculation. Because the pre-Islamic calendar used leap months, some reconstructions put it in June or July 622.

What the Hijra was

The Hijra was a move from persecution in Makkah to a town that had invited the Prophet ﷺ. Encyclopaedia Britannica's entry on the Hijrah describes it as a migration made "upon invitation in order to escape persecution." After arriving, the Prophet ﷺ negotiated the Constitution of Medina with the local clans, and Britannica notes that this established the Muslim community as a sociopolitical entity for the first time.

The Quran refers to the danger that came before it. In a translation of the meaning of Quran 8:30 (Dr. Mustafa Khattab, The Clear Quran, on quran.com), the verse reminds the Prophet ﷺ of the time "when the disbelievers conspired to capture, kill, or exile you."

The word hijra means emigration, and it was used for more than one journey. Britannica notes that it also applies to the earlier emigration of believers to Abyssinia (Ethiopia). When people speak of "the Hijra" as the start of the calendar, though, they mean the move to Madinah.

The journey from Makkah to Madinah

The most detailed account in the hadith collections is Aisha's narration in Sahih al-Bukhari 3905. She reports that the Prophet ﷺ told the Muslims he had been shown their place of migration in a dream: "a land of date palm trees, between two mountains." Many Muslims then migrated to Madinah ahead of him. Abu Bakr wanted to go too, and the Prophet ﷺ asked him to wait, because he hoped to be given permission to migrate himself.

The cave of Thawr

When the time came, the Prophet ﷺ and Abu Bakr left together. According to the same narration, they reached a cave on the mountain of Thawr and stayed there for three nights. Abu Bakr's son Abdullah spent the nights with them and returned to Makkah before dawn to hear what Quraysh were planning. Abu Bakr's freed slave, Amir ibn Fuhayra, grazed sheep nearby to bring them milk. They had hired a guide who was not Muslim, and after the third night he brought their camels and led them along the coast.

The Quran recalls the moment in the cave. In the translation of the meaning of Quran 9:40 (The Clear Quran on quran.com), the Prophet ﷺ reassures his companion: "Do not worry; Allah is certainly with us."

Arrival at Quba and Madinah

The people of Madinah went out to the lava field (the Harra) every morning to wait for him. In Sahih al-Bukhari 3906, Urwa ibn al-Zubayr reports that the Prophet ﷺ stopped with the clan of Banu Amr ibn Awf, "and this was on Monday in the month of Rabi-ul-Awal." He stayed there for ten nights and founded the mosque of Quba, then rode on into Madinah.

This narration is the hadith basis for placing the arrival in Rabi al-Awwal. It names the month and the weekday, but it does not give the day of the month.

Why the Hijra marks year 1

The Hijra marks year 1 because the Companions chose it over the other obvious candidates. In Sahih al-Bukhari 3934, Sahl ibn Sa'd says the Companions did not take as their starting date the day the Prophet ﷺ was sent as a messenger, or the day of his death, "but the day of his arrival at Medina." Imam al-Bukhari placed this report under the chapter heading "When did the Muslim calendar start?"

The count was not used from the start. Britannica says the Prophet ﷺ dated his own letters, treaties and proclamations by other events in his life. It was Umar ibn al-Khattab, the second caliph, who introduced the Hijra era in 639 CE. The reports about how and why he did so are covered in the sister post on how Umar adopted the Hijri calendar.

Umar did not start the count on the day of the journey. Britannica records that he "started the first year AH with the first day of the lunar month of Muḥarram," which corresponds to 16 July 622 in the Julian calendar. In other words, the event chose the year, and the existing order of months chose the first day. The reasons given for keeping Muharram first are explained in why the Hijri year starts in Muharram, not Rabi al-Awwal.

The dating debate: July or September 622?

Two different questions are often blurred together. One is when year 1 AH begins. The other is when the journey happened.

When year 1 begins

The start of year 1 is a fixed convention. The US Naval Observatory's Islamic calendar page states that the count of years begins with 1 Muharram AH 1, which "corresponds to Friday, 16 July 622 C.E. (Julian calendar)."

Some tables use the day before. R.H. van Gent of Utrecht University explains in his overview of tabular Islamic calendars that the epoch can be taken as 15 July 622 (the "astronomical" or "Thursday" epoch) or 16 July 622 (the "civil" or "Friday" epoch). This is one reason two converters can disagree by a day for historical dates.

When the journey happened

The date of the journey is less certain. Van Gent's note on the Arabian calendar in early Islam makes three points:

• The date of the Hijra "is not mentioned in the Qurʾān or in other early Islamic texts."
• Later traditions place the departure on 1 Rabi al-Awwal, the arrival at the outskirts of Yathrib on the 12th, and the entry into the town on the 16th.
• Until 10 AH the Arabian year was kept roughly in line with the seasons by adding a leap month every two or three years. Western dates computed as if the later rules applied "can be in error by one, two or even three lunar months."

The widely quoted "September 622" date comes from projecting the later calendar backwards from 16 July 622. Van Gent's reconstruction instead allows for the leap months (probably three) inserted between the Hijra and the Prophet's final pilgrimage. That moves the journey into June and July 622. He stresses that any reconstruction before the leap months were abolished "can only be regarded as hypothetical."

The back-projected column was calculated from the civil (Friday) epoch of 16 July 622, adding 30 days for Muharram and 29 for Safar, with weekdays computed from the Julian Day Number. The right-hand column is quoted from van Gent.

One detail is worth noticing. Sahih al-Bukhari 3906 says the arrival was on a Monday. The back-projected date for 12 Rabi al-Awwal falls on a Friday, while van Gent's reconstructed date falls on a Monday. That does not settle the question, but it shows why historians treat the September dates with caution.

Why neither date is "the Islamic New Year"

Whichever reconstruction you prefer, 1 Muharram is not the anniversary of the journey. It is the first day of the year in which the journey took place. The Islamic New Year page shows the next calculated date for 1 Muharram, and the sister post on what AH means explains how the year numbers are written.

A worked example: counting from 622

The Hijri year count is not simply "Gregorian year minus 622," because lunar years are shorter than solar ones.

Monday 9 November 2026 is 29 Jumada al-Awwal 1448 AH by the calculated Umm al-Qura calendar. Here is how the count gets there:

1. Days elapsed. From the civil epoch, Friday 16 July 622 (Julian Day 1,948,440), to 9 November 2026 (Julian Day 2,461,354) is 512,914 days.
2. Divide by the average Hijri year. The 30-year tabular cycle has 11 leap years, an average of 354 11/30 days (about 354.367 days) per year. 512,914 ÷ 354.367 ≈ 1,447.4 completed years.
3. Name the current year. With 1,447 years completed and part of the next under way, the date falls in 1448 AH.

Simple subtraction (2026 − 622) gives 1,404, which is 44 short. The difference comes from the Hijri year being about 11 days shorter than the solar year.

The Hijri date is calculated from the Umm al-Qura tables in the open-source hijri-converter library that this site uses. Day counts use Julian Day Numbers, and the average year comes from the 30-year tabular cycle. Local announcements may differ by a day.

Common questions

Did the Hijra happen on 1 Muharram?

No. Van Gent describes this as a common error. The traditions place the journey in Rabi al-Awwal, and 1 Muharram was chosen later as the first day of the year in which it happened.

Why do some sources say September 622?

September dates come from projecting the later, leap-month-free calendar back to 622. Using the Thursday epoch instead of the Friday one shifts them by a day. Reconstructions that allow for the old leap months put the journey months earlier.

Is 12 Rabi al-Awwal the date of the Hijra or the Prophet's birthday?

The two are different questions. The traditions summarized by van Gent place the arrival at the outskirts of Yathrib on 12 Rabi al-Awwal. The Prophet's birthday is a separate tradition about the same month, and Muslims hold different views on marking it. The sister post on Rabi al-Awwal covers the month.

Find any date counted from the Hijra

To see where a Gregorian date falls in the count that began in 622, use the Hijri date converter. It works with the calculated Umm al-Qura calendar for modern dates. For dates in the Prophet's lifetime, treat any conversion as approximate, for the reasons van Gent gives. If you want to mark a historical anniversary in your community, the Hijri date (such as 12 Rabi al-Awwal) is the one tradition preserves. Its Gregorian equivalent will move about 11 days earlier each year.