9:47 during the night. No different to a night India turn. Not saying it's right just saying we did the same in Europe on the way to TFS or LCA .
I'm guessing these are 2am pickups from home (little or no sleep), 24 hour layover with little/no sleep in the 12-16 hours preceding return pick up time, and landing red eye after 10 hour night flight to base. That is far more tiering than a night charter flight in Europe I would say.
Took me close 6 months to get fully back into a normal sleep cycle after my last stint at e/w long haul. I could sleep off a night "there and back" charter within a day or so.