Valid , but still it is always preferred to have early morning arrival because it hamper just the second half of day which generally people are adjusted with. There is no train from Ahmedabad- even from JP - AII which reaches Delhi between 6 to 8 am Except Rajdhani. If not Delhi Sarai , terminate at some other place and let the train reach Delhi before 7. So , train may start much before-5 hrs before 19:45 from ADI with a little speed up.