Stop assigning workouts to days. Build resilient sequences so clients never miss a muscle group, even if they miss a session.
Sequential Rotation Protocol
Do not assign these workouts to specific days of the week. Simply complete the workouts in numerical order. If you miss a day, do not skip a workout—just pick up with the next number in the sequence the next time you are in the gym. Once you complete the final workout, loop back to Workout 1.