Sundays will be my do-nothing day. It's important to have a designated rest point because no human can work at max efficiency all the time. Anyone who's ever ran a schedule will understand this. It's rare that everything happens on time. Slack is a natural accumulation, and if you want a foolproof schedule, then you must pencil in rest periods.
This doesn't mean I won't do anything for today. It just means I'm not locked into any one particular activity. I'm free to spend as much time doing whatever whenever.