KomOmbo temple

You can't really see in pic, but there carvings show the egyptian numbers and calendar. There were 3 seasons a year, each with 4 months of three weeks with ten days a week. This made 360 days a year - the remaining 5 were extra and added at the end to be like bank holidays to worship the local god. The seasons were 1. Flooding when the nile was flooded from africa, 2. Plantation as lands were fertile from water, and 3. Harvest. They knew the start of the year from the appearance of a star, also on the first day of the flood.