10:00am for the lawnmower, the grass isn't going anywhere and you shouldn't cut it wet, anyways.
The snowblower can be run any hour. The snow has to move, it can't pile up. Dom makes an excellent point though. Common sense applies. If there's an inch of snow and it's quit snowing, or is supposed to quit soon, it can wait.
That's assuming I live in close quarters. If I live in farm country, I can run whatever I want whenever I want to. Especially if I'm on a farm. Nobody is going to complain, either. They'll smile. "Nutsy across the street is plowing at 3:00 in the morning, he must have to go to work today." The smile is because he's badass.
