Shia Islamic calendar
The Hijri calendar itself doesn't change between traditions — Shia and Sunni Muslims use the same twelve lunar months. What differs is which days carry extra significance, and occasionally which date within a month is marked. This page covers the observances most specific to Shia Islam, mainly within the Twelver (Ithna Ashari) tradition, the largest Shia branch.
| Hijri date | Occasion | Significance |
|---|---|---|
| 1–10 Muharram | Mourning of Muharram | Ten days of mourning leading to Ashura, commemorating the Battle of Karbala. |
| 10 Muharram | Ashura | The martyrdom of Husayn ibn Ali, grandson of the Prophet, at Karbala in 61 AH — the central event of Shia religious memory. |
| 20 Safar | Arbaeen | Forty days after Ashura; marked by one of the world's largest annual gatherings, a pilgrimage on foot to Karbala, Iraq. |
| 28 Safar | Passing of the Prophet | In Shia tradition, the date of the Prophet Muhammad's death. |
| 17 Rabi al-Awwal | Mawlid al-Nabi | The Prophet's birthday in the Shia tradition (Sunni tradition marks 12 Rabi al-Awwal instead); also the birth date of Imam Ja'far al-Sadiq. |
| 15 Sha'ban | Mid-Sha'ban | Marked by both traditions as a night of forgiveness; Twelver Shia Muslims additionally commemorate the birth of Muhammad al-Mahdi, the Twelfth Imam. |
| 1 Ramadan – Eid al-Fitr | Ramadan & Eid al-Fitr | Observed as in the wider Muslim world; the 19th, 21st, and 23rd nights carry particular weight as candidates for Laylat al-Qadr. |
| 18 Dhu al-Hijjah | Eid al-Ghadir | Commemorates the event of Ghadir Khumm in 10 AH, regarded in Shia Islam as the Prophet's appointment of Ali ibn Abi Talib as his successor — one of the most significant days on the Shia calendar. |
This list isn't exhaustive — Twelver Shia practice also marks the birth and martyrdom anniversaries of each of the Twelve Imams throughout the year.
Prayer times & calculation
The prayer times page offers the Shia Ithna-Ashari (Jafari) calculation method as one of its options, which sets Maghrib slightly later than most Sunni conventions. Many Shia Muslims also combine Dhuhr with Asr, and Maghrib with Isha, rather than praying all five at strictly separate times.
See also
The events page lists Mawlid al-Nabi with both traditions' dates side by side. The months page covers the calendar structure itself, which is shared across all traditions.
Is the Shia calendar different from the Sunni calendar?
No — both use the same twelve-month Hijri lunar calendar. What differs is which additional days are observed, and occasionally which date within a shared month is marked, as with Mawlid al-Nabi.
What is Arbaeen?
Arbaeen falls on 20 Safar, forty days after Ashura, marking the end of the mourning period for Husayn ibn Ali. It's associated with one of the largest annual pilgrimages in the world, on foot to Karbala, Iraq.
What is Eid al-Ghadir?
Eid al-Ghadir falls on 18 Dhu al-Hijjah, commemorating the event of Ghadir Khumm — regarded in Shia Islam as the Prophet Muhammad's appointment of Ali ibn Abi Talib as his successor.