Who first came up with the 24-hour day? The Egyptians or the Sumerians?

[davidmich]

Who first came up with the 24-hour day? The Egyptians or the Sumerians?

Hi,

I have a read a few textbooks claiming that the Egyptians first came up with the 24-hour day. But while browsing online I came across many websites claiming the Sumerians were the first to introduce the idea. Which claim is correct and what proff is there for either claim’s validity?

davidmich

[Kimstu]

(We talked about this most recently a couple years ago, AFAICT.) First of all, it should be borne in mind that most ancient day-division schemes did not use intervals of equal length: an “hour” or similar unit was a portion of daytime or nighttime, so in summer the “hours” of daylight were longer while the “hours” of nighttime were shorter, and in winter vice versa. These are known as “seasonal” or “unequal” hours to distinguish them from “equinoctial” or “equal” hours that didn’t become standard in most civil timekeeping until the widespread use of mechanical clocks.

According to the Egyptologist Richard Parker, quoted in, e.g., Marshall Clagett’s Ancient Egyptian Science, the Egyptians from at least the late third millennium assigned twelve equal time-divisions to the night (and presumably also to the day). Criticisms of this interpretation in, e.g., an article in a recent volume Under One Sky have been made, but I don’t have the details handy. Certainly, the Egyptians were using this system by about a millennium later.

Ancient Babylonians (post-Sumerian) divided the whole day cycle (sunset to sunset) into 12 equal units called beru, but seem to have borrowed the 12 seasonal hours for daytime or nighttime from the Egyptians. Hunger and Pingree, Astral Sciences in Mesopotamia, p. 115:

Since the division of the nychthemeron [i.e., day cycle or our 24 hours] and the computation of seasonal hours is first attested in Egypt on the cenotaph of Seti I (-1302 to -1289) [BCE,] [… Babylonian texts using it] probably represent a Mesopotamian adaptation of the Egyptian practice.

I know of no evidence that the Sumerians (Mesopotamians using a non-Semitic language and dominating the region before about 2000 BCE) used the “12 seasonal hours of day or night” timekeeping system.

[davidmich]

Thanks kimstu. Very helpful.
davidmich

[Kimstu]

@davidmich

Thanks kimstu. Very helpful.
davidmich

Very welcome. What we’re here for.

[davidmich]

@Kimstu

(We talked about this most recently a couple years ago, AFAICT.) First of all, it should be borne in mind that most ancient day-division schemes did not use intervals of equal length: an “hour” or similar unit was a portion of daytime or nighttime, so in summer the “hours” of daylight were longer while the “hours” of nighttime were shorter, and in winter vice versa. These are known as “seasonal” or “unequal” hours to distinguish them from “equinoctial” or “equal” hours that didn’t become standard in most civil timekeeping until the widespread use of mechanical clocks.

According to the Egyptologist Richard Parker, quoted in, e.g., Marshall Clagett’s Ancient Egyptian Science, the Egyptians from at least the late third millennium assigned twelve equal time-divisions to the night (and presumably also to the day). Criticisms of this interpretation in, e.g., an article in a recent volume Under One Sky have been made, but I don’t have the details handy. Certainly, the Egyptians were using this system by about a millennium later.

Ancient Babylonians (post-Sumerian) divided the whole day cycle (sunset to sunset) into 12 equal units called beru, but seem to have borrowed the 12 seasonal hours for daytime or nighttime from the Egyptians. Hunger and Pingree, Astral Sciences in Mesopotamia, p. 115:
I know of no evidence that the Sumerians (Mesopotamians using a non-Semitic language and dominating the region before about 2000 BCE) used the “12 seasonal hours of day or night” timekeeping system.

I hiope you can help me with one more thing.

I found this description on the straight dope link you posted.

"
“The ancients counted on the spaces between the fingers. four spaces per hand, eight total. And the outside surfaces of each hand, two per hand. That gives six counting points per hand and twelve total. For them base twelve is equally natural.”
There appears to be something wrong with the phrasing. “And the outside surfaces of each hand, two per hand. That gives six counting points per hand “（see full quotation below”) The four spaces between the fingers I understand. Where are the other sites on the surface of the hand that make up 6 counting points per hand?

davidmich

[Swords_to_Plowshares]

The top of your hand and your palm.

[davidmich]

thanks.