It has 366 days in leap year. The February has 29 days.

How do u remember which month has 30 days and which month has 31 days.

American school children often have doggerels to help them to remember.

There are different versions,let me share one of them  with u:

It goes like this:

Thirty days has September, April, June and November. All the rest have thirty one, except February which has 28, in fine, till leap year makes it 29.