Why did people in ancient times decide to create a calendar?

The creators of the first calendar were the ancient Egyptians. At that time, Egypt had a peculiar climate. There was a period of drought that overflowed the Nile. In order to take these natural changes under your control, it was necessary to accurately calculate the periods of their beginning and end. For this reason, a calendar was created, with 12 months and 3 seasons. For the Egyptians, agriculture was very important, since without systematic sowing, field cultivation, irrigation and harvesting, the desired result could not be achieved. Time could have been wasted and the harvest would have perished.