Science in ancient Egypt
Egyptians believed in astronomy and always watched the night sky. They made the groups of constellations according to twelve zodiac constellations giving them the names of animals the outlines of which the constellations reminded.
They divided the whole sky into thirty six parts. They also made the tables of the stars position in every hour of the night according to fifteen periods. Egyptians were the first one to invent the sun calendar in the history of humanity.
The start of the year was the first day when the first star of Sotis or Sirius that was the reason for the Nile overflow according to Egyptians beliefs raised.
Egyptians had the year that consisted of 365 days. It was also divided into three seasons that were the overflow, crops and harvest. As you see all of them were connected with the agriculture and Nile. Every season had four months and every month consisted of thirty days. In fact they had three decades of ten days each. The last month had the additional five days that was called the small year.
The day of Ancient Egyptians also consisted of 24 hours but the period of hours was different and depended on the season of the year. They had the short day and long night hours in winter and long day and short night hours in summer. The years were counted according to the years of the pharaohs' reining.
Astronomy was always important in Ancient Egypt. That is why even the Pyramids were built according to the night sky forming the constellation. And Nile was playing the role of the Via Lacteal. Till nowadays scientists wonder how Egyptians managed to build pyramids with such correspondence to the night sky.