Question

Why does February have 28 days?

Answer 1

earth takes 365 1/4 days 2 take 1 revolution
like this 4 yrs r added & we get leap once in 4 yrs 
so feb has 28 days

Answer 2

The earth's revolution takes 365 days. After dividing it equally amongst 12 months it was found that 6 hours were still remaining. So every 4 years, the extra 6 hours multiply up to become 24 hours and add a day (6 multiplied with 2 equal to 24). And because February only had 28 days, it has 29 days every four years.