The ancient Egyptians were very clever people. They invented many things to make their life more comfortable.
CALENDAR: The ancient Egyptians created a calendar based on the farming season. There were 3 seasons - the flooding season, the planting season, and the harvest season. Each season was 3 months long. That added up to 360 days. The ancient Egyptians noticed they needed a few more days to fit the seasons. So they added 5 days, holy days, to thank the gods. So thousands of years ago, the ancient Egyptians invented a calendar with 365 days!