A Brief History of the Calendar

by David Harper, PhD, FRAS

Ancient Egypt

The civilisation of ancient Egypt left to posterity some of the greatest wonders of the world. The pyramids, the Sphinx and the Valley of the Kings still haunt us, and the golden face of Tutankhamun has been seen around the world. The Pharaohs sought immortality, and after 4000 years they found it.

The ancient Egyptians also bequeathed to us the idea which is at the heart of our calendar. Unlike the Babylonians, the Greeks and early Romans, they based their calendar upon the Sun alone. As the earliest great farming civilisation, Egypt was dependent upon the annual flood of the Nile which brought water and rich silt to the river's flood plain. Life in Egypt was controlled by the seasons, and hence by the Sun. The Moon played no part in the calendar.

The Egyptian year had twelve months, each of thirty days, plus an extra five days at the end of the year. These five days were associated with the birthdays of the greatest gods of the Egyptian pantheon and were given over to celebrations.

Thus the year was 365 days long. The Egyptians made no attempt to force their calendar to keep step with the actual seasons, as we do by adding leap-days. Instead, they accepted that the seasons would gradually become later and later with respect to the calendar, in a cycle that would take 1460 years to complete.

The Egyptians checked the relation of their calendar to the natural year not by observing the equinoxes and solstices but by the heliacal rising of Sirius, the Dog-star. This was the first sighting each year of Sirius in the morning sky just before sunrise.

Until the time of Julius Caesar, the Egyptian calendar was the only civil calendar in the ancient world in which the length of each month and year was fixed by rule instead of being determined by the discretion of priests or by the observations of astronomers. As such, it is the direct forerunner of our modern calendar.