How Leap Year Came About, Kinda
Published on Feb. 29, 2020
LAST FOR EIGHT YEARS
There Will Not Be Another Leap Year Until 1904.
It Therefore Behooves the Ladies to Take Advantage of the Present Opportunity to Propose – a Rare Occurrence.
Headlines in July 2, 1896, issue of the Converse County Herald published in Lusk attempts to explain the origin of Leap Year. The article reads:
The leap year which now begins is, however, to a certain extent peculiar, since another will not occur for eight years. Such an interval has occurred twice before in the history of Scotland, and only once in the history of England, and two centuries will ellipse before it occurs again.
The last year of the present century, 1900, will not be a leap year, but 2000, the last year of the succeeding century, will. The year 2100 will again be a common year, so the next period of seven consecutive common years will be between 2096 and 2104.
The rule by which this seemingly arbitrary interference with an established order of things is regulated is comparatively simple, but its history is in many respects both curious and interesting.
As everyone knows, the earth revolves round its axis, and also travels round the sun, the one revolution causing the alternation of day and night, the other that of the seasons. From the earliest times men have made use of both these series of changes as a means of reckoning time, and had there been a simple numerical relation between them, there need never have been any trouble with leap years and such devices.
Unfortunately, however, this is not at present the case. The number of revolutions which the earth makes when it goes once round the sun, instead of being a whole number, is a number and a fraction, or in other words, the earth goes ‘round the sun in 365 days five hours and 48 minutes 40 seconds, or 365.2422 days. This was not, however, discovered in a day. Various guesses were made at the proper length of the year, and calendars were drawn up in accordance with them.
But in the course of time the error accumulated, with the result that the seasons changed places, and the vernal equinox, instead of remaining at affixed place in the calendar, moved backward or forward, according as the approximation was in excess or defect and extra days had to be intercalated or omitted to set things right.
By the time of Julius Caesar, the Roman year, which consisted of 355 days, had worked loose by three months, so the winter months had been carried back into autumn. In order to prevent such confusion in the future, with the aid of Sosigenes, he fixed the length of the year at 365-1/4 days, or three years of 365 days, followed by one of 366.
At the same time, to bring back the equinox to its proper place, he intercalated 90 days into the current year of 355 days, making it 445 days, probably the longest year on record. This was the Julian calendar, and to it we owe to this day the leap year which comes every fourth year.
But the approximation on which the calendar was based, though much more accurate and convenient than any that had preceded it, gave too long a year by the difference between 365.25 and 365.2422, the error amounting to a day in 128 years.
In the course of the centuries, the equinox gradually receded toward the beginning of the year. Caesar had fixed it on March 25. By the time of the council of Nice, and by 1582 it had receded to March11. In order to restore the equinox to the position it occupied in 325, when the council of Nice had drawn up regulations for the fixing of Easter, Pope Gregory, in 1582, directed 10 days to be suppressed, and as the error was found to amount to three days in 400 years, he laid down that in the future the last year of every century should be an ordinary year, unless it is divisible by 400, in which case it was to be a leap year. Thus 1900 will be an ordinary year, but 2000 will be a leap year.
Pope Gregory’s correction gives an average year of 365.2425 days, or 26 seconds longer than the true year. These odd seconds will amount to a whole year m 3,323 years, and it has been proposed to allow for this error by providing that the year 4000, and all its multiples, shall be common years. But this would be a pedaunic foresight, and it is unnecessary to discuss the question whether the year 4000 ought or ought not to be a leap year.
In ages yet to come when the friction of the tides has so retarded the rotation of the earth that 365 days make a year, leap years will be unnecessary. But that is a still remoter contingency, and in the meantime Pope Gregory’s calendar is likely to remain in its present form. – Edinburg Scotsman.