Hijri calender has twelve months with 29 or 30 days. When the Crescent Moon is visible after sunset on the evening of the last day of the month mostly 29th day, that day is the 1st day of the new islamic month.
| Month Names | Days |
|---|---|
| Muḥarram | 29/30 |
| Ṣafar | 29/30 |
| Rabī‘ al-awwal | 29/30 |
| Rabī‘ ath-thānī | 29/30 |
| Jumādá al-ūlá | 29/30 |
| Jumādá al-ākhirah | 29/30 |
| Rajab | 29/30 |
| Sha‘bān | 29/30 |
| Ramaḍān | 29/30 |
| Shawwāl | 29/30 |
| Dhū al-Qa‘dah | 29/30 |
| Dhū al-Ḥijjah | 29/30 |
