On the 2nd of Spring, the very first day you are able to play after the opening sequence. You can remove any item from your Toolbox and use it an unlimited number of times. Because the scene with the Mayor is an important one, you are unable to faint from exhaustion. It does take a little while to level them all up. But can be worth it in the long run because it will allow you to take advantage of smashing large rocks, and breaking up tree stumps earlier in the game. This will work as long as you do not go outside after you first wake up.