4 Fridays are in August 2010.
March 2010 contained five Mondays.
52
November: 5 Mondays December: 4 Mondays.
Mondays in each month in 2010:Jan - 4Feb - 4Mar - 5Apr - 4May - 5June - 4July - 4Aug - 5Sept - 4Oct - 4Nov - 5Dec - 4