| Hijri Month | Starts On | Day of Week | Days in Month |
|---|---|---|---|
| Muharram 640 | 1-Jul-1242 | Tuesday | 30 days. |
| Safar 640 | 31-Jul-1242 | Thursday | 29 days. |
| Rabi al-awwal 640 | 29-Aug-1242 | Friday | 30 days. |
| Rabi al-thani 640 | 28-Sep-1242 | Sunday | 29 days. |
| Jumada al-awwal 640 | 27-Oct-1242 | Monday | 30 days. |
| Jumada al-thani 640 | 26-Nov-1242 | Wednesday | 29 days. |
| Rajab 640 | 25-Dec-1242 | Thursday | 29 days. |
| Shaban 640 | 23-Jan-1243 | Friday | 30 days. |
| Ramadan 640 | 22-Feb-1243 | Sunday | 30 days. |
| Shawwal 640 | 24-Mar-1243 | Tuesday | 29 days. |
| Dhu al-Qidah 640 | 22-Apr-1243 | Wednesday | 30 days. |
| Dhu al-Hijjah 640 | 22-May-1243 | Friday | 29 days. |