p90x day 7

How can i do p90x and work at the same time?
I work on the weekends fri sat and sun 12 hours per day but the p00x program says 6 days a week with an optional rest day on the 7th. So i want to see if any one has any suggestions as to how to do the workouts i need to do and work at the same time without fatigue which can lead to me stopping.
You can do the workouts before or after work. I like to do them between work and dinner. Not only need to you need time in your schedule for the workouts you also need time in your schedule for following the nutrition plan.
P90X Day 7