1) For waiting of course press select, choose the amount of time you want to wait.

2) Hit guide button and A at the same time. You will notice time is going way faster by the light change. If you press B on the guide button you can see the timer going down faster, and return to normal speed as that would be interrupting the glitch.

3) This is very useful for waiting for stores to restock. Also if you are a werewolf or Vampire you can easily wait the time faster than before to turn back to normal.

It's a very small and easy to do tutorial, very helpful for the things listed above.
Cutting wait time in half will save you time and possibly make you money faster.

If your married you can keep doing this method to speed up time and have your wife give you a cut of earnings, also store keepers will have a fresh income to spend on things you can sell.