Your questions: Where did minutes and hours originate?

A question I received this weekend: “Where did minutes and hours originate?”

Look no further than to the page on NIST’s site for general history of clocks, calendars and daylight saving time:

“A sundial described in 1300 BCE reveals that the Egyptians determined a daily cycle to be made up of ten hours of daylight from sunrise to sunset, two hours of twilight and twelve hours of night. Their calendar year was divided into 36 decans, each ten days long, plus five extra days, totaling to a 365 day year. Each decan was equivalent to a third of the zodiacal sign and was represented by a decanal constellation. The night corresponded to about twelve decans, half a day to eighteen decans. Similar to the system used in Oriental clocks, the night was thus divided into twelve hours, with seasonable variations of the hour’s length. Later, Hellenistic astronomers introduced equinoctial hours of equal length.

“The Babylonians (in about 300-100 BCE) performed astronomical calculation in the sexagesimal (base-60) system. This was extremely convenient for simplifying time division, since 60 is divisible by 2, 3, 4, 5, 6, and 10. What we now call a minute derives from the first fractional sexagesimal place; the second fractional place is the origin of the second.”

If you’re interested, I also recommend “The Experience and Perception of Time” from the Stanford Encyclopedia of Philosophy.