How many days' gap was there between the days on which P and T worked overtime?

According to question , we can say that
P, Q, R, S and T finished the work, working from Monday to Saturday, one of the days being a holiday, each working overtime only on one of the days.
There was a two days' gap between the days on which P and Q worked overtime.
P worked overtime the next day of the overtime day of S.
Therefore , required answer will be three days .