What is the leap year? Origins and Beliefs

Bi-sextilis, du nom romain, le second sixième jour, est une invention romaine, qui se pratique depuis 1582; ce qui permet d’équilibrer la différence entre le nombre de jours inscrits au calendrier et le nombre de rotations de la Terre autour du soleil : 365, 2425.

Except that the story of this additional day goes back to the time of Julius Caesar in 45 BC when he (Julius Caesar) called upon a Greek astrologer, Alexandrian of Alexandria, to settle a delay observed in the years Solar and calendar years in a new calendar; The Julian calendar. Inspired by the Egyptian calendar, to find a solution, the scientist proposes to establish years of 365 days to which will be added, every four years, this intercalary day. In the era of Pope Gregory, in 1582, the calculation of Sosigene of Alexandria will be denied to establish an average duration of the year at 365, 2419 and not 365, 2425.
This new Gregorian calendar will preserve the leap year principle, adding an exception, one day less every 100 years, and will be adopted throughout Europe in 1582.
Since then, the Catholic Church has established only the multiple years of 4 but not 100, and the multiple years of 400, would all be leap-frogs. Thus, the years 1600 and 2000, were leap years, and thus for all the years of every 4 years: 2008, 2012, 2016, and to come, 2020,2024, 2028 ... etc. From there, it is obvious that February 29 is a day that happens only every 4 years.
In the Roman period, this additional day was placed six days before the calendars of Mars (bi-sextilis, the second sixth day), a day corresponding, roughly, to the period of February 28th of the Gregorian calendar. Instilled as a "bonus" day, on February 29, between February 28 and March 1, this day is talked about especially among those born that day, and therefore celebrate their birthday only once every 4 years .
In Ireland, tradition says that Saint Patrick decreed Feb. 29 of the leap year, a day in which women could themselves apply, thus balancing roles. This custom has even been adopted by neighboring cultures. Thus in Scotland, but also in Denmark or Finland, men refusing this request were required to pay a fee. In some European regions, it was therefore customary to pay for the purchase of 12 glove pairs for the woman rejected.
In the Maghreb, the month of February, a deficit month even in leap year, is the subject, many sayings or legends about the "days of borrowing". The narratives relating to these days are known in almost all the Mediterranean countries and are often associated with the myth of Ajouzaa. An old woman, who believed last winter, came out one day of sunshine in the fields and laughed at him. Yennayer, displeased, took two days to furar (February), and set off, in revenge, a great storm which carried the old woman in her enormous waves. P. Galand Pernet, who carried out an important investigation into this myth of the Old, concluded that he was very antiquated and indigenous, while that of the days of borrowing, often associated with him, was of foreign origin .