DEFINITION

Hijrah refers to travel from one land (or country) to another, specifically if the decision was done to help you protect your faith by leaving one land where it is difficult to be a Muslim, to go to another land where it is easier to practice Islam.

The Hijrah commonly refers to the Prophet’s immigration to Madinah after 13 years of persecution in Makkah. The hijrah marks the beginning of the Islamic calendar, known as the Hijri calendar. The names of the months in the calendar, from the first to the twelfth, are: 

1. Muharram; 
2. Safar; 
3. Rabi al-awwal; 
4. Rabi al-thani; 
5. Jumada al-awwal; 
6. Jumada al-thani; 
7. Rajab; 
8. Sha'aban; 
9. Ramadan; 
10. Shawwal; 
11. Dhul-Qa'dah; 
12. Dhul-Hijjah.

Resources:

1. The Beginner's Guide to Understanding Islam