On the nature of time: Hours

Time passes.

Well, that seems to be a simple enough statement on the face of it. Most of us have a sense of past, present, and future, and the language to refer to the differences.

I've been doing a little research recently on how time is marked in different cultures, both currently and in the past: Seconds, minutes, hours, days, weeks, months, years, decades, centuries, millenia, etc. I've posted previously on how the seasons are marked, and the differences in determining when a particular season begins.

Recently, our AODA study group discussed the calendar of Coligny, a lunisolar calendar that may or may not have been Gaulish in origin (it's an interesting exercise to look up everyone's opinion on the origins and details of that calendar). That re-sparked my interest in the nature of recording time, and sent me down all sorts of different paths in short order. This is part of one of those paths.

I know from earlier studies that there is more than one way to track time during the day, and more than one meaning to the word hour in western culture.

The obvious meaning refers to the mean solar hour, which is 1/24^th of the length of the mean solar day (solar days actually vary in length during the year). We understand that the hour has 60 minutes, and that each minute has 60 seconds in it. We're taught this in school (at least the part about 60 minutes and 60 seconds, and 24 hours in the day), and might learn later that there are atomic clocks out there that measure and report a fixed, precise time that at least the U.S. government agrees on (my computer has a program that synchronizes the computer's clock to one of those atomic clocks). The day begins at midnight, and the hours run from 1 to 12 to reach noon, and then from 1 to 12 again to reach midnight (unless you're using a 24 hour clock as the military and some computer centers do. Oh, and Hong Kong as well).

Astronomy and astrology both use this definition of hour, historically and currently, for taking measurements and recording events.

But that's not the only way to measure the hours, or to determine when the day begins.

There's a concept of unequal hours that goes back a long time. Under this concept, the periods of daylight and darkness are each divided up into a predetermined number of units (called hours in western culture for convenience), and because the period of daylight and period of darkness may be of different lengths, the hours of daylight may be different lengths from the hours of darkness.

This use of hour was applied to the Canonical Hours, the marking of when to perform particular sets of prayers in the various Christian churches, such as Prime (first hour of daylight), Terce/Tierce (third hour of daylight), Sext (sixth hour of daylight/midday), None[s] (ninth hour of daylight). We still keep one of those words in common use, None[s] (noon), although it's been moved up to midday from its later position). The hours of nighttime were divided into a set number of Watches, Vigils, or Nocturnes, depending on the convention in use.

This use of hour is also applied to the Planetary Hours, which is used to determine which of the seven planets (Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon) govern a particular time of day, so that you can know what hour a particular activity is best performed during. As with many mathematical concepts these days, there are websites, spreadsheets, and computer programs available that can help you determine exactly when these planetary hours fall on a given date.

The planet that governs the first planetary hour of daylight also governs that particular day: The Sun governs the first planetary hour of daylight on Sunday, the moon governs the first planetary hour of daylight on Monday, Mars on Tuesday, Mercury on Wednesday, Jupiter on Thursday, Venus on Friday, and Saturn on Saturday. This is [supposedly] based on the ancient Chaldean order of the planets for astrology.

The day might be considered to begin at different times as well. The so-called Italian system starts the day at either nightfall or sunset (not necessarily considered the same time), the Babylonian considers the day to start at daybreak or sunrise, and the so-called Local system considers the day to start at local midnight (the modern system), all either for equal or unequal hours.

Going east to Asia, China and Japan also have both concepts of hour, as either an equal division of the mean solar day, or an unequal division of daylight versus nighttime. The major difference is that, traditionally, the total number of divisions in a day is 12, rather than 24. The Japanese hour system, further, counts backwards from 9 to 4 for the first half of the day, and again from 9 to 4 for the second half of the day (1 to 3 are reserved for religious reasons, the number of bell strokes to call Buddhists to prayer). I have seen a picture of a Japanese 12-hour clock, but it is a full day clock, not a half day clock like most western clocks.

Time to go — it's Noon/Sext/Midday/the 9^th hour of the day/the 3^rd hour of daylight/time to make and eat lunch.