As far as I'm concerned, unless you're offering first class (and perhaps even then), time spent in coach for a business trip on a red-eye should count as work time. Let them have the day - or work from home. I, for one, would find it cruel to arrive at 7 with virtually no sleep and be expected to be at work at 1 PM... how late do you then expect them to stay? Do you want to risk a lawsuit if one of them falls asleep driving & kills someone?