I like to rub the pork on Saturday and baste on Sunday morning. I then put the pork in the oven on 250 degrees F (120 degrees C) for 3 hours then set to go to warm. That way it is ready when I come home from church. While it is on warm I baste again and prepare my side dishes.
You can apply rub for a shorter time and then apply baste but you won't get the flavor into the meat, it will only be on the outside of it.