moon phases |
| 1. Muharram | 7. Rajab |
| 2. Safar | 8. Sha'ban |
| 3. Rabi' al-awwal (Rabi' I) | 9. Ramadan |
| 4. Rabi' al-thani (Rabi' II) | 10. Shawwal |
| 5. Jumada al-awwal (Jumada I) | 11. Dhu al-Qi'dah |
| 6. Jumada al-thani (Jumada II) | 12. Dhu al-Hijjah |
(Due to different transliterations of the Arabic alphabet, other spellings of the months are possible.)
Each month starts when the lunar crescent is first seen (by a human observer's eye) after a new moon.
Although new moons may be calculated quite precisely, the actual visibility of the crescent is much more difficult to predict. It depends on factors such as weather, the optical properties of the atmosphere, and the location of the observer. It is therefore very difficult to give accurate information in advance about when a new month will start.
Furthermore, some Muslims depend on a local sighting of the moon, whereas others depend on a sighting by authorities somewhere in the Muslim world. Both are valid Islamic practices, but they may lead to different starting days for the months.
Years are counted since the Hijra, that is, Mohammed's flight to Medina, which is assumed to have taken place 16 July C.E. 622 (Julian calendar). On that date AH 1 started (AH = Anno Hegirae = year of the Hijra).
This information taken from The Islamic calendar at WebExhibits.org.