Ten persons L, M, N, O, P, Q, R, S, T, and U were born on two different dates, 15 and 30, of five different months: January, March, April, September, ...

Ten persons L, M, N, O, P, Q, R, S, T, and U were born on two different dates, 15 and 30, of five different months: January, March, April, September, and November, but not necessarily in that order.

• L was born on the 15th of a month that has 31 days.
• There are three persons born between L and P.
• Four persons were born between P and O.
• O was born before L.
• The number of persons born after O is equal to the number of persons born before N.
• One person was born between P and R.
• M was born before T but not in January.
• T was born before P.
• U was born before S on the same date.

Question: How many persons were born between T and N?