I would say Ananthapuri should take the timing of 17:10 pm departure from MS to reach Tirunelveli at 03:30 am and NCJ at 04:40 to reach Trivandrum at 06:30 am. Return of Ananthu should be 18:30 from TVC to reach MS at 07:00 am. It would be the best timing when Ananthu is made as SF and Quilon express should be converted as Quilon mail and should start MS at 21:50 pm to reach Quilon at 11:55 and return to start from Quilon at 13:55 to reach MS at 04:25 am.