I've designed the split to give you two rest days per week, and you'll get the best results by following it as laid out in the trainer. However, it's better to squeeze any missed workouts in on a rest day than to skip them entirely! If you absolutely don't have time for today's leg workout, get to the gym tomorrow on your rest day and bust it out.
PH3: Layne Norton's Power And Hypertrophy Trainer, Day 10
Today's leg workout may have you hobbling around tomorrow, but that's OK—you've got a rest day to recuperate afterward!
Day 10: Squat, Bench, Leg Hypertrophy