Muslims use the Hijrah calendar.
Al Hijrah is the first day of Muharram which is the first month of the Islamic calendar.
It is a time when Muslims remember when Prophet Mohammed travelled from from Mecca to Medina.
What is the story?
People in Mecca were being nasty to Prophet Mohammed because he was preaching a new religion – Islam. The people from the city of Medina asked Mohammed if he wanted to migrate to their city of Medina. Mohammed said yes and left Mecca before the people could murder him.
In Medina the Prophet Mohammed started an Islamic community and people all over Arabia started talking about and listening to information about Islam.
On this day, Muslims say special prayers and read from the Quran and read stories about the Prophet Mohammed’s migration to Medina.
Read the full story of the life of Mohammed.