Instead of messing up 12626 train TT if they want to follow the best ZBTT would be for the train to leave TVC at 10:00 AM and arrive NDLS at 10:00 AM (1 hr 15 mins speeded up) and then return to leave at 16:00 PM to arrive TVC at 16:00 PM (48 hours) - and then go for PM for 16:30 PM from next day 09:30 AM and SM at NDLS from 10:30 AM to 15:30 PM , in that case if it gets delayed during fog it does not have to arrive TVC at midnight
Also...
more... closely follow TN, telengana and KA and arrive last set at NDLS and leave as first set from NDLS to arrive TVC on the third day early evening like old TT.
Or another option is 12625 has to leave at 07:00 AM sharp from TVC (good office time) and reach NDLS at 07:00 AM third day and leave at 16:00 PM evening and arrive TVC at 16:00 PM (to avoid delays)