Why in February 28 days?
February – the most unusual month of the year. He appeared in the calendar later than others, and the number of days in it changed more. Initially, the ancient Roman calendar year began on March 1, shared for ten months and lasted only 304 days. About 690 before. NS. The ruler of the ancient Rome Numa Pubrugi added to the calendar January and February. February was devoted to the God of the underground kingdom of Fabrus, and his name comes from the Latin word Februare – "Clean". He became the last month of the year, so he had only 28 days.
In 46 BC. NS. Another calendar reform was held by Julius Caesar. The basis of the Julian calendar was the tropical year with a duration of 365,2422 days. But the calendar year should contain an integer day, therefore a cycle of four years was introduced: three ordinary years of 365 days, and the fourth, leap, – 366. At the same time, the average duration of the calendar year 365.25 days is quite close to the tropical year. Julius Caesar also ordered the number of days in months on this principle: in odd – 31 days, in even – 30. February in the usual year had to have 29, and in the leap – 30 days. The new calendar began to act on January 1, 45 years BC. NS., But after a year, Julius Caesar died, and an annoying mistake was brought to the calendar – Roman priests declared a leap not every fourth, and every third year. The situation was corrected by the emperor August. In gratitude for this, the Roman Senate in 8 BC. NS. Renamed a month of sextilis in Augustus. But it was 30 days, and the ancient Romans believed that even numbers bring misfortune. Therefore, by August, another day was added, reducing it from February. Since then, in February 28 days in the usual years and 29 – in leaps.