Measurement of Time Units in Ancient Egypt

A Tale of Two Generations: A Story from the Ancient Indus Valley Civilization

Commodities work as messengers between cultures. They bring messages from one culture to the other and from one era to the other era. It is only through commodities produced by a group of people that we understand the way they lived, the material they used, the beliefs and values they had and the way they understood reality. Hence, primitive cultures communicate with us when during an excavation we find reminisce of their civilization in the form of their commodities. The story of civilizations is not told by the books of Plutarch and Herodotus alone, but also by the objects that we find from archaeological excavations. How beautifully, the famous Poet, Rashid has narrated this fact:

…how after thousands of years,

From the alleys of a buried city,

The grains of my Cup, Vase and other artifacts,

Are discovered. As if these objects are the

Memories of this ruined city.

In the same manner, the life of Egyptians, not thoroughly manifested in the historical accounts, is manifested through the findings of excavations; Egyptian culture reveals its meaning in the excavated objects. Among these objects, clocks and calendars enjoy a great importance, for these objects inform us about the concept of time, which Egyptians maintained for thousands of years.

Like all ancient people, Egyptians also had a lunar calendar which was in the later years, replaced by a fixed calendar, known as the Civil Calendar. This new calendar divided the year into 365 days. Each year, according to this new calendar, had three seasons of four months each. Each month was of thirty days and three weeks. Each week was of ten days and there were 36 weeks in the year. Since the number of days in the twelve months made for only 360 days of the year, therefore the remaining five days were added to the calendars as feast days. These days marked the end of the year and were reserved for festivities and celebrations.

The first season started with the rise Sirius star on the horizon. This stellar event did not only have astronomical significance, but it was also accompanied by a rise in the water levels of Nile. The season thus started, with the rise of Sirius star, was named, 'Inundation' for waters began to rise in Nile, to cover the land adjacent to the river. The second season was termed 'Emergence', for during this part of the year, land reemerged from the water that remained inundated during the four months of the Inundation season. During this season Egyptians sowed seed to grow their crops, to be harvested in the next season. The third season was termed as 'Low Water’, because the waters of Nile remained low during the four months of this season, and during this season crops were harvested. Since, the natural year is one fourth of a day longer than the civil year, therefore Egyptians added a day to the year after a period of four years. The seasons of Egyptian were aligned with their economy which was largely agricultural. The month was divided into 30 days just because of the administrative purposes in a centralized society.

Egyptian Clocks were mainly of three types; star clocks, sun dial clocks and water clocks. Star clocks were used to measure the length of the night hours. Egyptians divided their day, from Dawn to Dawn, in 24 hours. These 24 hours consisted 12 day hours and 12 night hours, and each hour had varied length.

The day was divided into 12 day hours. These twelve day hours were the twelve stages of the journey of the sun through duat, the nether world, according to the Egyptian religion. Egyptians believed that the sun travelled through the nether world during the day time. These hours were marked by shadow clocks and the sun dial clocks. Water clocks were also used for the determination of the day hours. Water clocks were of two kinds. Water outlet clocks, that measured the length of hours by the passage of water from an aperture that was built in a vassal containing water in it, and water intake clocks that measured the length of time by comparing the quantity of water coming in through aperture, with a graduated scale. The shadow clocks were installed to measure the time with the help of the length of shadows during the day time.

According to Egyptian system, the first night hour started with the advent of darkness after the sunset. The length of the first night hour was indeterminate, for it continued till the arising of first star on the eastern horizon. Accordingly, the second hour started with the arising of the 1^st star on the eastern horizon and ended with the arising of the 2^nd star on the horizon. Continuing thus, the twelfth hour ended with the arising of the twelfth star on the eastern horizon, and that was also called the morning star.

The time elapsed between the arrival of the 1^st night star and the beginning of darkness after the sun set shortened each day. Hence, on the tenth day, the last day of a week, for Egyptian week was of 10 days, the 1^st night star, after remaining the leading night star for 10 days, gave way for the second night star of the previous week. And in this new week, the second night star of the previous week appeared to become the leading star. Consequently, the length of the first night hour on the first day of the new week was the longest.

On the other hand , the morning star that rose heliacally on the first day of the week, rose comparatively earlier in the following days of the week, hence, at the end of the week it rose quite earlier , to make it the longest last night hour of the week. Consequently, due to the earth’s motion round it axis, a new star took the place last week’s morning star, and became the morning star.

Hence after each week, after a period of 10 days, each star moved ahead and secured a place further ahead in this arrangement. In this way, the star that was the morning star during the first week, after 110 days, moved ahead to become the first night star. The night hours were not of equal length, but their length varied with the variation in the time elapsed between the sunrise and the sunset, due to the earth’s motion round the sun.

The seasons of the Egyptian calendars were meant for describing the periods of time that were important for agricultural activity. They told us about the rise and fall of the waters of Nile. Moreover, on these calendars certain days were reserved for the important common feasts, and were called feast days. These feasts were fifteen in number, and had direct relationship with the economic activities of the Egyptian society.

Now the question is what mad Egyptians to develop such a complex system of time measurement?

It is difficult to know the cause behind developing this system and not another, but one can determine the cause for developing a time measurement system as such. The reason can be determined if one looks at ancient Persian emperor Ardeshir’s statement about the possibility of an empire. He says:

“There is no empire possible without power, no power possible without military, no military without wealth, no wealth without agriculture, and no agriculture is possible without justice. Hence, according to this legendary emperor, whom Persians greatly revered, justice is the most important factor in the formation of an empire, and consequently in the formation of a civilization. And, one can assume that this system of time measurement was also developed to maintain justice in the society.