How do you count fortnights in a month?

A fortnight is a period of two weeks, or 14 days. In a typical month with 30 days, you can count two complete fortnights (28 days) and have 2 days remaining. In a month with 31 days, there are still two complete fortnights, with 3 days left over. In February, which has 28 days (or 29 in a leap year), there is exactly one fortnight, with the remaining days being fewer than another full fortnight.