| Hijri Month | Starts On | Day of Week | Days in Month |
|---|---|---|---|
| Muharram 639 | 12-Jul-1241 | Friday | 29 days. |
| Safar 639 | 10-Aug-1241 | Saturday | 30 days. |
| Rabi al-awwal 639 | 9-Sep-1241 | Monday | 29 days. |
| Rabi al-thani 639 | 8-Oct-1241 | Tuesday | 30 days. |
| Jumada al-awwal 639 | 7-Nov-1241 | Thursday | 29 days. |
| Jumada al-thani 639 | 6-Dec-1241 | Friday | 30 days. |
| Rajab 639 | 5-Jan-1242 | Sunday | 29 days. |
| Shaban 639 | 3-Feb-1242 | Monday | 30 days. |
| Ramadan 639 | 5-Mar-1242 | Wednesday | 30 days. |
| Shawwal 639 | 4-Apr-1242 | Friday | 29 days. |
| Dhu al-Qidah 639 | 3-May-1242 | Saturday | 30 days. |
| Dhu al-Hijjah 639 | 2-Jun-1242 | Monday | 29 days. |