4 weeks is good. There is no harm in going a little over. Just make sure maybe every week, you unwrap it and make sure its not turning gray. Make sure his color is good, if it starts turning gray, then you need to bring him in (kind of no choice on that one); because that means it might have some sort of infection. Also, I usually gave bandit little baths then
Also, your going to need a UVA light. The sun is good and the
UVB light is good, but hes going to need a UVA light also. Along with that, you need to pick up Calcium supplement to sprinkle on his crickets (and if needed, veggies), because the lights cant exactly provide the full calcium he needs. Also, make sure that at least one side of his tank is at MINIMUM 100 degrees (some will suggest higher than that even)...and the MINIMUM for the other side would be 80 (again, some will suggest higher).
Good luck! Keep us posted!