"هجري" refers to the Islamic calendar, which is a lunar calendar consisting of 12 months in a year of 354 or 355 days. It is used primarily to determine the proper days of Islamic holidays and rituals, such as رمضان (Ramadan) and عيد الأضحى (Eid al-Adha). The calendar starts from the year of the Hijra, the migration of the Prophet محمد (Muhammad) from مكة (Mecca) to المدينة (Medina) in 622 CE. The months in the هجري calendar include محرم, صفر, ربيع الأول, ربيع الآخر, جمادى الأولى, جمادى الآخرة, رجب, شعبان, رمضان, شوال, ذو القعدة, and ذو الحجة. Each month can have either 29 or 30 days, depending on the sighting