January 31
February 28 / 29 (with leap year)
March 31
April 30
May 31
June 30
July 31
August 31
September 30
October 31
November 30
December 31
January
1, and it's February, but only during a leap year
12 Months
All of them
No. Only one extra day is added in a leap year, and it is added to February, bringing it from 28 to 29 days. No other months have days added, so they are all the same length as any other year.
Seven months.
All months have twenty-eight days.Only February has only twenty-eight days.
Seven months have 31 days while the remaining five have 30.
Jan, Mar, May, July, Aug, Oct, and Dec have thirty-one days.
There are five months in a year which have five weeks and these months are January, March, August, October and December. This is due to having thirty-one days instead of the normal thirty day month.
Because they were bad
January, March, May, July, August, October, and December have thirty one (31) days.
Thirty-one weeks is seven and one quarter months. It is not seven and three-quarters months because 31 weeks X 7 days in a week / 30 days in a month = about 7.25.