Explanation

Rajab is the seventh month of the Islamic calendar. 

Isra and Miraj (Muhammad's journey from Mecca to Jerusalem and then through the seven Heavens) took place in Rajab.

Must remember all 12 Islamic months name

List of Islamic Months

1. Muḥarram, محرم الحرام
   
2. Ṣafar, صفر المظفر
3. Rabi al Awwal ربیع الاول
4. Rabi al Sani ربیع الثانی
5. Jumada al Awwal جمادی الاول
6. Jumada al Thani جمادی الثانی
7. Rajab, رجب المرجب
8. Shabanشعبان المعظم
9. Ramadan(fasting), رمضان المبارک
10. Shawwal شوال المکرم
11. Dhu al Qadah ذوالقعدۃ الحرام
12. Dhu al Hijjah ذوالحجۃ الحرام:

Each month begins approximately at the time of the new moon.