Question

why there is 28 days in feb

Answer 1

There are 28 or 29 days in February due to the leap year.

Answer 2

It's the Romans' fault. Our modern calendar is loosely based on their old, confusing one. Though records on the Roman calendar are sparse and sketchy, legend has it that Romulus, the first king of Rome, devised a 10-month lunar calendar that began at the spring equinox in March and ended with December. It is unclear whether there were any official months between December and March, but it's likely they were left off because the wintertime wasn't important for the harvest.