Seven Years Without a Birthday

This is an adaptation and condensation of an April 1892 article from an unidentified journal. It was sent to us by Mother Kalliniki of Holy Nativity Convent. Some addenda are also presented.

The solution to the puzzle lies in a not very widely- known fact that the year 1800 was not a leap year and 1900 will not be. February of this year [1892] had 29 days, as it will in 1896, but in 1897, 1898, 1899, 1900, 1901, 1902, and 1903 it will not.

Another question that puzzles many people is when a century ends, and why this century is named the nineteenth although it is 1892. The common mistake is to conclude that the century ends with the year in which the eighteens or nineteens are completed, that is, with 1899 or 1999. But this is not the case. A century is a group of a hundred years. The first century began with the year 1 and must end with the year 100, the second century begins with 101 and ends with 200, and so on, each century taking its name from the year which completes it. The nineteenth century, then, ends with the year 1900, and the twentieth begins with January 1, 1901. The twentieth ends with the year 2000, and the twenty-first begins with January 1, 2001.

But getting back to leap years, why do we need them? Why aren't all months the same length? These questions have to do with the motions of the earth, which moves in two ways. It spins on its axis, which causes us to have 24-hour units of time that we call days. It also moves in a big circle around the sun, and the time it takes to complete that circle we call a year. That complete circle is made in nearly 365¼ days. So the complicating factor here is that the year is not exactly 365 days long. And a calendar must adjust for the nearly ¼ of a day (nearly 6 hours) extra. Leap years are the device we use to adjust for those 6 hours, and the "nearly" is the reason 1800 and 1900 are not leap years.

About half a century before the birth of our Lord Jesus Christ, Julius Cæsar set out to end the confusion about the modes of reckoning the months and days of the year. The system he devised, with the assistance of astronomer Sosigenes, has been named the Julian calendar. It fixed the length of the year at 365¼ days, and the odd quarters were gathered up into a day at the end of every 4 years. So after three years of 365 days, there was one of 366 -- what we have come to call "leap year."

Then in the year of our Lord 325, the great ecumenical council of Nicæa was held. One part of their deliberations had to do with the proper time for celebrating Pascha. It was determined that it should fall on the Sunday after the full moon which is on or comes next after March 21, with the additional stipulation that it must be after Passover. A difficulty lay in the fact that the "full moon" of the Church was not the "full moon" of the calendars and almanacs.

As time passed, it became evident that the calendar year had been made too long at 365¼ days. The exact time it takes for the earth to make its way around the sun is 365 days, 5 hours, 48 minutes, and 46 seconds. The difference between those two numbers was causing a cumulative error which the leap year device did not take care of completely. The leap-year day was being added too often -- once too often in about 128 years.

In the sixteenth century Pope Gregory XIII directed that a calendar be made which shortens the year so that the solstices (when the length of daylight is greatest and least) and equinoxes (when the days and nights are of equal length) would no longer fall back (occur too early by the calendar). It was noted that one day in 128 years amounted to slightly more than 3 days in 400 years. These three days could be got by grouping the century years ⁽²⁾ into fours, like the years in general, and making one in four of thema leap year. Regular years are leap years if they are evenly divisible by four. Century years are leap years only if they are evenly divisible by 400, and therefore occur only every 400 years. So 1800 and 1900 are not leap years, but 2000 is. ⁽³⁾ The Gregorian century-year/leap-year device does not completely correct for the ¼ day over 365. The error still amounts to 26 seconds per year, or one day in 3,323 years.

The arrangement of months in the Gregorian calendar is entirely arbitrary. There is nothing in nature to fix their order or to determine when any one of them should begin. Up until 1752 the legal year in England began with March 25. There is no reason why the spring equinox should fall on March 21 any more than on the 11^th or 25^th, but, since the Council of Nicæa had made the calculations of the date of Pascha dependent on March 21, it was decided (by Pope Gregory and his assistants) that it should be returned to that date. This meant dropping 10 days out of the calendar. The pope therefore decreed that October 5, 1582, should be October 15^th.

The "New Style" calendar was adopted at once by most Catholic countries, but in England not until 1752, when September 3^rd became September 14^th. ⁽⁴⁾ Russia still uses the "Old Style." ⁽⁵⁾ Because of their counting the year 1800 as a leap year, they are now 12 days behind and are likely to be 13 days behind eight years hence in 1900, which they will count as a leap year, but those using the Gregorian calendar will not.

The day added to the calendar in a leap year is called an intercalary day. February has all along been the month to receive that day. But February has in other ways been quarried to the "benefit" of the rest of the calendar. January and February came into the calendar together, with January the first and February the last. February was then made the second month. Julius Cæsar assigned 31 days to January, March, May, July, September, and November, and 30 days to all the others except February, which was given 29. This was the case in all but leap years, when February had 30 days.

This very nice, highly regular scheme was upset to gratify the vanity of Augustus. He noted that Julius had changed the name of the month Quintilis (originally the fifth month) to Julius (our July) in his own honor. So Augustus, though he had done nothing to reform the calendar, had to have his namesake month as well. Not only did he choose to rename Sextilis (originally the sixth month) to Augustus (our August), but it had to be lengthened by a day so that Julius would not be a longer month then Augustus. Where did the extra day come from? Poor February, of course, was reduced to 28 days.

But the changes did not end there. Since September had originally been assigned 31 days, and it seemed awkward to have three months in succession with 31 days (July, August, and September), September and November were changed to 30 days and October and December to 31.

1. I.e., February 29, 1796, since this was written in 1892.

2. A century year is the last year in the century, the one which has two zeros as its last two digits.

3. The next century year that will be a leap year is 2400.

4. By that time the difference in calendars was 11 days.

5. That was in 1892. Russia adopted the Gregorian calendar in 1918.

Excerpt from an Introduction (by Jonathan Brent) to
The 1918 Diary of Tsaritsa Alexandra

Where the Name "Leap Year" Came From

Accounting for the Present Difference between the
Julian (Old Style) and the Gregorian (New Style)
Calendars, with Projections for the Next Millennium
by Century