Yeah you set yourself up for too big of a challenge! I would think you would need at least three days lead time to allow your body to shift into autolysis and the desire for food to diminish before going to work. Working in a restaurant is especially difficult since the aromas will be triggering your hunger response is will be extremely difficult to manage. I speak from experience. The other day I went to a meeting and it happened that everyone wanted to grab a bit to eat...so I went with them to get take out at a mexican food place. I thought that since I was on my 18th day of the cleanse that it wouldn't be too much trouble. When I walked into the place my sense of smell was bombarded by the aromas and I had to leave after only a minute or two. Then for a couple hours I had to battle major cravings because the aromas triggered my desire for food. I was like an alcholic that was only 18 days sober going into a bar thinking it was ok as long as I didn't drink.
Maybe your constitution is stronger than mine and you will fair better but to be on the safe side you may want to ask for some extra days off . You might also try getting you days off back to back even if that means having to work a long stretch later. Once you get in there and start work you may get used to it...but make sure you keep a thermos of lemonade handy and maybe drink a P&B just as your shift starts so that your stomach feels full.