Why 28 days in February?

Answer 1

Prior to Julius Caesar, the year had 12 months of 31 or 29 days (355 days in all), plus an extra "month " added in from time to time. In those days the Roman calendar began in March - with the Spring, rebirth after the "dead" of Winter and so on. July, which would have been the fifth month was named Quintilis, August (sixth) was named Sextilis and the prefices for September to December are still present in the current names of the months. Note that the adjustment was carried by February, the last month of the year.

However, the decision to add the extra month to allow the calendar to "catch up" with the Earth's orbit was down to politicians and they introduced the extra month or withheld its introduction on political expediency. So what has changed in politics since then? And this did cause the calendar to drift

In Egypt, meanwhile, Eudoxus had calculated that the year was 3651/4 days long and there had been an attempt to have cycles of three years of 365 followed by one of 366 (decree of Canopus). Although that was unsuccessful, Julius Caesar was sufficiently impressed so that when he returned from his Egyptian conquest he sought seek help from Alexandrian mathematicians to sort out the Roman calendar. The first eleven months were made more or less equal (30/31 days) with February picking up the adjustments, as before.

The start of the year was moved to January much later, but the month lengths were not changed,

Incidentally, there is an urban myth that Augustus Caesar "stole" a day from February so that his month would not be shorter than Julius Caesar's. He could have really put the boot in by stealing it from July!