Many people from different countries who follow the Julian calendar celebrate Christmas on December 25 and others like in Eritrea who follow the Gregorian calendar celebrate the day on January 7. In Eritrea the Geez calendar is the foundation of all Christian religious occasions like Christmas, Easter, Kudus Yohannes and others.
The Geez calendar is derived from the older Alexandrian calendar. The new year begins from Meskerem first (September) and ends in the added five days of Pagumien (it becomes 6 days in every four years) and every month has 30 days. That means the Geez calendar adds a leap day every four years and that results alternate calculations in determining the date of the Annunciation of Jesus.