Ancient egyptian dating system
As they made no provision for a leap year, the calendar and the seasons drifted out of step, and by the end of the Old Kingdom there was a discrepancy of five months.
The Egyptian calendar also took on other important functions within Egyptian life specifically in dealing with the astrology of the people.
So they introduced a calendar containing twelve months each with thirty days, and each month containing three weeks of ten days, and then five days of public holidays to bring the year to three hundred and sixty five days.The beginning of the year, also called "the opening of the year", was marked by the emergence of the star Sirius, in the constellation of Canis Major.The constellation emerged roughly on June 21st., and was called "the going up of the goddess Sothis".This first rising of a star in the dawn sky in the East, just before Sunrise, is called its To the Egyptians it represented the end of the time the star had spent in the Underworld.
Almost as soon as the first people began to settle in the valley of the River Nile, before 4200, they noticed that the heliacal rising of Serpet, after a period of seventy days of invisibility, always came a few days before the start of the annual inundation.
The stars near Polaris, ), circle round Polaris but do not rise and set; the stars further away from Polaris rise in the East and set in the West, just like the Sun and Moon.