‘Time is an illusion, lunchtime doubly so.’ –Douglas Adams
Today hardly anyone notices the equinox. Today we rarely give the sky more than a passing glance. We live by precisely metered clocks and appointment blocks on our electronic calendars, feeling little personal or communal connection to the kind of time the equinox once offered us. Within that simple fact lays a tectonic shift in human life and culture.
Your time — almost entirely divorced from natural cycles — is a new time. Your time, delivered through digital devices that move to nanosecond cadences, has never existed before in human history. As we rush through our overheated days we can barely recognize this new time for what it really is: an invention. (…)
Mechanical clocks for measuring hours did not appear until the fourteenth century. Minute hands on those clocks did not come into existence until 400 years later. Before these inventions the vast majority of human beings had no access to any form of timekeeping device. Sundials, water clocks and sandglasses did exist. But their daily use was confined to an elite minority.
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The 12-hour clock can be traced back as far as Mesopotamia and Ancient Egypt: Both an Egyptian sundial for daytime use and an Egyptian water clock for night time use were found in the tomb of Pharaoh Amenhotep I. Dating to c. 1500 BC, these clocks divided their respective times of use into 12 hours each.
The Romans also used a 12-hour clock: daylight was divided into 12 equal hours (of, thus, varying length throughout the year) and the night was divided into four watches. The Romans numbered the morning hours originally in reverse. For example, “3 am” or “3 hours ante meridiem” meant “three hours before noon,” compared to the modern usage of “three hours into the first 12-hour period of the day.”
Also: The terms “a.m.” and “p.m.” are abbreviations of the Latin ante meridiem (before midday) and post meridiem (after midday).
