Every four years, what is for many people their least-favourite month gets longer. February 29th 2024 is the leap day of a leap year; a year in which an extra day is added to the calendar in order to synchronise it with the seasons. 

THE JULIAN CALENDAR

Egyptian, Hindu, Chinese and Hebrew calendars incorporated temporary months so that festivals would take place in the same season every year. The early Romans, for example, created a twenty-two or twenty-three-day month every second year. The Egyptian pharaoh Ptolemy III devised a leap year calendar as early as the 3rd century BCE, but the idea is more often associated with Roman emperor Julius Caesar. In 45 BCE, he simplified the previous system by adding one day every fourth year. 

THE GREGORIAN CALENDAR

Unfortunately, as Persian astronomer Omar Khayyam was to accurately measure in the 11th century, the length of the year is slightly less than 365.25 days. Adding an extra day every four years results in about three surplus days being added throughout four hundred years. So in 1582, Pope Gregory XIII established that every centennial year would not be a leap year except if the centennial year could be divided by four hundred. This is why the year 2000 was a leap year but 1800 and 1900 weren’t.

CATHOLIC motives

This reform became the canon law of the Catholic Church. However, other churches resented that. Some Protestants were worried that the new calendar was a plot to return them to Catholicism! Therefore, Britain and its colonies did not adopt the Gregorian calendar until 1752, by which time it was necessary to delete eleven days all at once; so the 2nd of September 1752 was immediately followed by the 14th of September 1752. Today, the vast majority of countries use the Gregorian calendar as their civil calendar. Those that have not adopted it are Ethiopia, Nepal, Iran and Afghanistan.

TRADITIONS

Leap day traditions are associated with February being a month of love. Bachelor’s Day is an Irish tradition ‘allowing’ women to initiate dances and propose marriage only on February 29th. If the proposal is refused, the man is expected to buy the woman a dress or gloves to compensate her for the embarrassment. In the town of Aurora, Illinois in the US, single women are given the right to arrest single men on leap day and fine them four dollars, while in Anthony in Texas, a huge birthday festival is held specially for people born on February 29th.