Aseem ji Generally charting time for the trains departing before noon 12.00 is previous night after 20.00 hrs (between 20.00 and 22.00 hrs) from Monday to Saturday.
On Sunday PRS counters are open up to 14.00(at some stations) and 16.00 hrs. So charting is done after 16.00 hrs on Sunday for Monday morning trains.
There are some exceptions in above, in some trains charting is done same day 2-3 hrs before the departure time for morning trains.