Why does February have 28 days
Any popular anomaly has a number of theories regarding its origin and the month of February is no different either. February is the second month of the year in the Roman calendar and it consists of 28 days every year except the leap years which has 366 days and the extra day is added to the month of February thus making it a 29 day month every four years.
One theory states that in order to honor Augustus Caesar, the eighth month of the year was renamed from Sextilis to August and a day was subtracted from the month of February to add to August. This was done because Julius Caesar already had the seventh month honoring his name. However, August was at that time a 30 day month unlike July, which had 31 days in it. Thus, to place the prestige of Augustus Caesar at the same height as that of Julius Caesar, August received the day that February lost. This theory is quite popular but its reality is unconfirmed.
A theory which is backed up more by history states that the 28 day month of February was already present way before Julius and Augustus Caesar. In fact, it was only a ten month calendar that the Romans kept, which started in March and ended in December. Numa Pompilius in the eighth B.C. century added the two months of January and February to the Roman calendar as he thought that it was stupid and lazy to have such a long time within the year out of the calendar. Numa estimated that a year is 355 days long and thus he recreated the calendar by adding seven 31 day months and four 29 day months but he still needed one month with 28 days to make the year of 355 days. The other months were of uneven numbers to avoid bad luck through the use of even numbers, but February was chosen to be the only month to bear the unlucky even number of 28 days due to necessity. The specific reason for choosing February was because it was the last month of the year back then and also because it was one of the coldest months.