Our Divisions of Time
How familiar to us are the names of the months, and the days of the week, and yet how few of us know to whom we owe these names or what a wealth of meaning they possess. They have come to us from the past, from the time when people worshiped many gods and explained the wonders of nature in their own simple way. But before listening to the stories which these names can tell us, we ought first of all to remind ourselves of the way in which our divisions of time came into being.
We all know that the earth turns round on its own axis, giving us periods of light and darkness, which we call day and night. The word " day", which comes from a very, very old word meaning "to shine", really means, of course, the time during which the earth is lit up by the sun, but it has also come to mean the time which the earth takes to revolve, as from sunrise to sunrise, sunset to sunset, midday to midday. The Greeks measured the day from sunset to sunset, the Romans from midnight to midnight, the Babylonians from sunrise to sunrise. The day, in this sense, became the first measurement of time.
The day, however, is a very short period, so another measurement was taken for a longer space of time, and this measurement was suggested by the changes in the moon. It was noticed that the moon altered in shape, beginning with the new moon, waxing to the full moon and then gradually waning. So the space of time from one new moon to the next--about 29-1/2 days--was called a moonth or month, afterwards known as the lunar month (lunar, from Latin; Luna = moon).
The next measurement of time, the year, was suggested by the seasons. People noticed that there was a period of heat and a period of cold, a time when the trees and plants put forth their buds, and a time when all Nature seemed to die, and these periods became known as the Seasons--Spring, the time when plants spring up; Summer, the mild or gentle season; Autumn, the season of increase, when the fruits of the earth are gathered in; Winter, the windy or cold season.
It was found that the time from one Spring to the next, or from one Winter to the next, was about twelve lunar months, and these twelve months were known as a year. The change of season is, of course, due to the movement of the earth round the sun, and the exact time taken by the earth is 365 days, 5 hours, 49 minutes. Now, a year of twelve lunar months is only 354 days, and the result of this difference was that the months got ahead of the seasons, and in a year or two, when, according to the Calendar, the Spring months had come, it was really still Winter. In order to put this right, the lunar year (moon year) was made longer by having an extra month put in every now and then. In this way the lunar year was made to correspond more nearly to the solar year (sun year), that is, the year of 365 days. The Jews put in a month seven times in every nineteen years, and the Greeks a month three times in every eight years. The Romans had first of all a year of only ten months, beginning with March. Then they added two months, making a year of 355 days.
But even now the number of days was short, and to make up for the loss, days were added from time to time. These extra days, however, were added in such a way that they led to great confusion, and the Roman Dictator, Julius Caesar, in order to do away with this confusion, decreed that the year 46 B.C. should consist of 445 days, and fixed the length of future years at 365 days. But since the earth's journey takes 365 days, 5 hours, 49 minutes, a quarter of a day was still lost each year, so Caesar ordered an extra day to be put on to February every fourth year, making that year what we call Leap Year, because the Calendar makes a "leap" of one day. This new Calendar is called the Julian Calendar, after Julius Caesar.
The lunar year, that is, the year of twelve months, seemed at last to be of the right length, but even now there was a very tiny mistake. You will have noticed that 5 hours, 49 minutes was taken as a quarter of a day, but it is short of 6 hours by 11 minutes. A very small difference you will say; but after several hundred years it amounted to ten days, so that the lunar year was now too long. In 1582 Pope Gregory ordered that ten days should be left out in that year, and the day after the 4th of October was called the 15th.
The change was not made in England until 1751, when eleven days were dropped, and it led to a great deal of discontent among uneducated people, who thought that these days had been stolen from them! In order to prevent the mistake occurring again, it was arranged that instead of every fourth year being a leap year, the years which end in 00, as 1700, 1800, 1900, should not be leap years.
