One of the oldest chronological systems was the Egyptian calendar. It was based on observations of the Sun, Sirius (the brightest star of the Northern Hemisphere, personifying the Egyptian goddess Isis) and Neil. The calendar of Ancient Egypt arose in the IV. BC. e. and belonged to the solar type. The year in it consisted of three seasons, each of which included four thirty-day months:
1)that-January,
faory-february,
atir-mart,
Hoyak-April;
2)tibi-may,
mehir-june,
famenot-july,
pharmuti-August;
3)pahon-september,
Piney-October,
epiphy-November,
Mesori-December.
The year lasted the same as now - 365 days. Such a system of time calculation existed before the introduction of the Muslim calendar.