Seven friends P, Q, R, S, T, U and V were born in seven different months March, April, June, July, August, September and December not necessarily in the given order. R was born in the month having days less than 31 days but before August. Only three friends were born after T. U was born just before V but after T. More than three friends were born between P and S. R was not born just before T and T was born before S.

How many friends were born between Q and S?