| Hijri Month | Starts On | Day of Week | Days in Month |
|---|---|---|---|
| Muharram 637 | 2-Aug-1239 | Tuesday | 30 days. |
| Safar 637 | 1-Sep-1239 | Thursday | 29 days. |
| Rabi al-awwal 637 | 30-Sep-1239 | Friday | 30 days. |
| Rabi al-thani 637 | 30-Oct-1239 | Sunday | 30 days. |
| Jumada al-awwal 637 | 29-Nov-1239 | Tuesday | 30 days. |
| Jumada al-thani 637 | 29-Dec-1239 | Thursday | 29 days. |
| Rajab 637 | 27-Jan-1240 | Friday | 30 days. |
| Shaban 637 | 26-Feb-1240 | Sunday | 30 days. |
| Ramadan 637 | 27-Mar-1240 | Tuesday | 29 days. |
| Shawwal 637 | 25-Apr-1240 | Wednesday | 30 days. |
| Dhu al-Qidah 637 | 25-May-1240 | Friday | 29 days. |
| Dhu al-Hijjah 637 | 23-Jun-1240 | Saturday | 29 days. |