The month of February has 28 days because, when the first Roman calendar was introduced, it was the last month of the year, starting in March. Consequently, it seemed logical to adjust its duration, rather than that of another month, so as to make the calendar coincide with the solar year. The Roman calendar was developed at the time of Romulus (8th century BC) and the month of February was added, together with that of January, by his successor and second king of Rome, Numa Pompilius. The duration of February did not change when the Roman calendar was replaced by the Julian calendar (1st century BC), which, however, introduced the principle of the leap year, establishing that February can last 28 or 29 days. The principle was accepted, with some modifications from the Gregorian calendar in force today.
The duration of the month of February: the Roman origins
As we all know, February is the second month of the year and, unlike other months, it only has 28 days (29 in leap years). The reasons for this peculiarity must be traced back to the history of ancient Rome. According to tradition, the first calendar, known as the Roman calendar, was developed at the time of Romulus in the 8th century BC. C. and divided the year into ten months, from March to December. The winter months were not numbered, in the sense that they did not have a name: they were almost a time outside of time.
After Romulus, Numa Pompilius became king of Rome, who ordered the calendar to be rearranged and to add two winter months: January and February, the first dedicated to the god Janus, the second to purification. Since in Latin it is said to purify February, the month was called February. Purification rituals were held in honor of the Etruscan god Februus and of the Roman goddess Febris.
The year began in March and February was, accordingly, the last month. For this reason, it was logical to adapt its duration so as to make the calendar coincide with the solar year (i.e. with a complete revolution of the Earth around the Sun). In other words, since it was necessary to cut days from a month, it was logical to choose the last one.
According to another theory, February was shorter because it was considered an unlucky month. However, this is a hypothesis without supporting data.
However, it is certain that the calculation carried out at the time of Numa was imprecise and, to make the calendar year coincide with the solar year, an intercalary month (i.e. an additional month, which did not exist every year) called Mercedonio was added periodically. In the 2nd century BC. C. the beginning of the year was moved to January (it was established that the consuls and other magistrates would take office in January and no longer in March), but the duration of the months was not changed.
February and the Julian calendar
In the 1st century BC. C. Julius Caesar had the calendar rearranged by an astronomer from Alexandria, Sosigenes. The new calendar, called Julian in honor of Caesar, eliminated the intercalary month and, to adapt the duration of the year to the earth’s revolution, introduced the leap year, i.e. establishing the addition of a day every four years. It was chosen to add it to the shortest month, namely February. The leap year system was accepted, with some modifications, by the Gregorian calendar, developed in the 16th century on the basis of the Julian one and now adopted in much of the world.
Augustus and the duration of the months
According to some scholars, February originally had 29 days and 30 in leap years. The duration would have been shortened by Augustus to add a day to the month of August, dedicated to him, which previously had 30 days and was therefore shorter than July. According to this theory, Augustus would have wanted to prevent “his” month from disfiguring itself compared to July, dedicated to Julius Caesar, and therefore would have ordered the change. This is, however, an unproven hypothesis: according to many scholars, already in the first versions of the Julian calendar February only had 28 days and 29 in leap years.
