Leap-Years and their Occasional Omission

Abstract

AFTER the present year there will be no leap-year, at any rate, in the many countries which now observe the Gregorian style, until 1904; in other words 1900, which would, by the Julian rule, have been a leap-year, will be a common year and have to content itself, like the three years preceding and the three years following it, with the ordinary number of three hundred and sixty-five days. Only once has a similar omission occurred before since the reformation of the calendar in England, viz. in 1800, a year remarkable enough in other respects. The change was originally made in 1582; but as centuries divisible by four hundred without remainder were to be considered leap or bissextile years by either reckoning, there was only occasion, in 1700, when a year was observed as such in England, which was a common year in southern Europe; for 1600 was, as 2000 will be, a leap-year by the Gregorian as well as by the Julian reckoning. Few persons seem to recollect that the change which was effected at Rome in 1582, and followed in this country in 1752, was twofold in its character. If it be desired to make the date in any year correspond exactly with the season of the year, this can of course be done for any future time by inserting or omitting certain intercalary days in the calendar in some such way as is directed by the Gregorian rule to which we are now accustomed, and which was devised by Clavius under the authority of Pope Gregory XIII. But if this had not been done in past ages through want of exact knowledge of the true length of the year, or from any other cause, the fact may either be accepted as inevitable and therefore regretfully disregarded, or we may, if we wish, so change the existing dates in the year from which we start, as to make the seasons correspond with what they were on these dates at some definite period in the past. This is what was actually done, the period selected being A.D. 325, the year of the first great Council of the Church held at Nicæa in the reign of Constantino the Great. At that time the vernal equinox fell on March 21; and as, in consequence of the observance of the Julian length of the year in the interim, it fell in 1582 on the nth of that month, it was decreed that in the following autumn ten days should be struck out of the calendar, by calling the day after October 4 the 15th, so that in future the vernal equinox (and all the other seasons) should fall as they had clone in 325. This arrangement involved another inconvenience besides the awkward enumeration of days in that year, viz. that the seasons were made to disagree appreciably with their dates in the years and centuries immediately preceding the time of the change. However, on the whole, it was thought to be the best arrangement, and it was gradually followed by most of the nations of Europe excepting Russia. In England the change was made in 1752, and the calendar in all respects assimilated to that of the New Style, adopting the Gregorian rules. As in accordance with these, 1700 had not been a leap-year, whereas in England by the Julian reckoning it had been, the two calendars now differed by eleven days; the Act of Parliament therefore, which ordered the change, enacted that the day after September 2, 1752, should be called the 14th.