Liturgically speaking, we have one great celebration that starts with the Easter Triduum where we remember Christ’s death and resurrection and continues for 7 weeks culminating in Pentecost with the coming of the Holy Spirit and the commencement of the Catholic Church. Christmas is a lesser celebration when we give thanks for Jesus coming into the world. It only dates back to the 4th century. Celebrating birthdays was a Roman confection: neither Jews nor Greeks celebrated birthdays. Nobody knew the date Jesus was born and when Christianity became the religion of the Roman Empire, he had to be allocated a birthday. We mark Christmas with trees, presents, overeating and being kind to our mothers-in-law, and we eat vast quantities of chocolate at Easter, but these are largely to do with pagan spring and winter festivals that were absorbed into the Christian calendar to help with evangelisation.