Regardless when it becomes your turn you decide if you want to adventure or rest. Would be simple enough to say "I'm using my sword to kill goblin. For my turn, I'll Rest."
This is similar to how you would use the staff to up the magic level right before resting and claiming the spell. The staff only affects the magic level for you, not the other players, so I don't see why you would ever want to do that and then actually roll the dice.