(Paris) Le 29 février est un jour insolite du calendrier qui n’existe que tous les quatre ans… enfin presque. Voici quatre choses à savoir sur ce jour supplémentaire des années bissextiles.
Multiple de 4, mais non de 100
L’Égypte ancienne tenta de mieux faire coïncider son calendrier avec le cycle naturel des saisons. Mais c’est à Jules César qu’on doit l’introduction des années bissextiles, avec « la réforme du calendrier romain […] in the year 708” (the introduction of the Julian calendar in 45 BC), explains the Institute of Celestial Mechanics and Ephemeris Calculation (IMCCE), attached to the Paris Observatory.
In years of 366 days, the additional day was then a double of Februarus 24, i.e. “the sixth day before the Calends of March”, hence the French word bissextile, when the English language opts for the more colorful ” leap day » (day that jumps).
With the transition to the Gregorian calendar in 1582, “the additional day was added at the end of the month of February, on the 29the day,” continues the IMCCE.
Since the Earth does not take exactly 365 days and 6 hours to revolve around the Sun, but 365 days 5 hours, 48 minutes and a few seconds, not all years that are multiples of four are leap years. Years also multiples of 100 are not. So 1900 and 2100 do not have February 29th.
Aging four times slower
This is what the magnetic French actress Michèle Morgan, who died at 96, praised. “This privilege of aging four times slower than others is the first in the long series of strokes of luck that I have had throughout my existence,” rejoiced the woman who shares this unusual day of birth with the composer. Italian Rossini, French actor Gérard Darmon, Spanish Prime Minister Pedro Sanchez, American rapper Ja Rule and comedian Sugar Sammy.
With a one in 1506 chance of being born on February 29, only a few million people in the world have this original date of birth. Precisely, 27,832 in France since 1968, according to INSEE data.
On the border with Mexico, those born on February 29 will still be entitled to a dedicated festival in the small Texan town of Anthony, self-proclaimed world capital of leap years since 1988.
” Would you marry me ? »
In Ireland, the government paid a bonus of 100 euros in 2004 for children born on this extra day to mark the tenth anniversary of the International Year of the Family, declared in 1994 by the United Nations.
The Irish also continue to have in mind an old tradition, which dates back to the 5th century, making February 29 the “ Bachelor’s Day ” Or ” Ladies Privilege »: day when women could propose to men in marriage. A refusal was rewarded with a gift, according to some, or with a fine, according to others. In 2010, it inspired “Give me your hand” (“Give me your hand” (“Give me your hand”) Leap Year ), a romantic comedy with Amy Adams… named “worst film of the year” by Time Magazine.
Year 2000 bug
As the new millennium approached, all concerns were focused on a possible major computer failure on the 1ster January. It was finally February 29, 2000 that caused fear. Police computers were temporarily blocked in Bulgaria, as were Japanese weather services, the American Coast Guard’s message archiving system and the Montreal municipal tax service, according to AFP archives.
The computer system of Paris parking meters had to be corrected machine by machine, because it did not predict February 29, 2000.
Indeed, 2000 might not have been a leap year, since years that are multiples of 100 are not… Unless they are also multiples of 400, like 2000 (or 1600 or 2400). You follow ?