A Matter of Time... Part the First
MeiLin's request for help with developing a calendar for the Greater Kingdoms brought about this train of thought, and my quest for answers to ways to mark the passage of time in the broader senses led me to research that piqued my interests. So now, I'm sharing what I've uncovered with you. It's a very l-o-n-g story, so I'll probably break it down into several installments.
Calendars and Timekeeping are closely related, for the development of one led to the development of the other -- and both led to the development of mathematics, accurate methods of travel, and the influences of the Catholic Church.
So -- Obviously, Calendars came first. And the phases of the Moon were the first used indicators. Despite -- or perhaps because of -- its easy use as a measure of time, the moon proved to be a trap fro naive mankind. While the phases were convenient worldwide cycles which anybody could see, they were an attractive dead end. What hunters and farmers needed most was a calendar of the Seasons -- a way to predict the coming of rain or snow, of heat and cold. How long until the proper time to plant crops? When to expect the first frost? The heavy rains?
For these needs, the moon gave little help True, the moon would cycle with an uncanny correspondence to the menstrual cycle of women, because a sidereal month (the time it takes for the moon to return to the same position in the sky) was a little less than 28 days, and a pregnant woman could expect her child after ten of these moon-months. But a solar year -- the proper measure of days between returning seasons -- measures 365 days, 6 hours, and 14 minutes. The cycles of the moon are caused by the moon's movement around the Earth at the same time the earth is moving around the sun. The moon's orbit is elliptical, and departs by an angle of about five degrees from the earth's orbit around the sun. This explains why eclipses of the sun do not occur every month.
The discomfiting fact that the cycles of the moon and the cycles of the sun are incommensurate would stimulate thinking. Had it been possible to calculate the year, the round of seasons, simply by multiplying the cycles of the moon, mankind would have been saved a lot of trouble. But we might also have lacked the incentive to study the heavens and to become mathematicians!
The seasons of the year, as we now know, are governed by the movements of the earth around the sun. Each round of the seasons marks the return of the earth to the same place in its circuit, a movement from one equinox (or solstice) to the next. Mankind needed a calendar to find his bearings in the seasons.