Don't think they will change day of operation as BBS TPTY is running on Sun and reverse on Monday. As the slot is for 4 days now 2 days from Chennai and 2 from TPTY there are less chances of extention and giving a new slot in evening. SCR is now concentrating on giving slots for cargo movement. Unless the train is made daily from 2 days extention and change is slot is ruled out. Extention either to SBC and TPJ seems bleak as there are other inter city in that section coinciding with the same timings. Tambaram can be considered if SR obliges