In all honesty, no ranger will be up checking permits for people trying to enter the Whitney Zone prior to sunrise.
If you need the extra hours, I don't think your in much danger entering one-two hours before your permit is active (pending an active effort to acquire a permit for the early day)... After all, the ageless wisdom of "YOLO" can be applied.
I'm kidding about the YOLO thing. That's quintessentially absurd...
