Repeating Tasks, without set days/times

A key feature I would love to see that I haven't seen yet, is the ability to set thinks to recur, but not with set days/times. Basically I'd like a task to automatically "refill" in my role for the next week etc, but I want to be able to pick when it is. For instance if I'm planning on going to the gym 3 days a week, rather than a specific recurring time, I'd like Weekplan to give me 3 instances of "Go To The Gym" and every Sunday I could place them where I want on the schedule. As a freelance filmmaker, having the ability to flexibly schedule recurring tasks easily would be huge.
I understand that I could just manually re-make these tasks every week, but that would be a giant chore.