Help with Butt Timing

At 225 it could easily take over 10 hours to get over 200 internal. If you don't want to start it the night before, you might kick it up to 275. The higher smoking temps will reduce time with no ill effect on the pulled pork.

On my UDS I would be starting that puppy around 10 or 11 the night before. Gives you 11 - 16 hours of cooking time with extra time in case you hit a long plateau and time to let it rest. It's going to depend on your pit and your system for cooking things on it.
That's if you keep that temperature at 225 as much as possible.

You could start it about 5 or 6 in the morning to be on the safe side.
After you toss it in the cooler crack open a beer and wait for family to arrive. If properly insulated the butt can rest for hours and hours, even after 6 hours it should still be more than hot enough and taste damn fine. Make sure to wrap in a good thick towel or 2 towels and a cooler and not an oven and it will hold temp perfectly, just don't open the cooler at any time during the rest, only right as you are pulling it out.

I have learned my lesson with smoking butts. You need to start this thing at around midnight. It is going to take at least 10 to 12 hours at 225. I would consider kickin it up a notch to 250. With this starting time and given it takes 12 hours it should come out sometime between noon and 2. If it's goin too fast drop the temp down to 225. Pull it and slam it in the cooler wrapped in foil and a beach towel. When you pull it out at 5 it will be steamin. I have slammed these things in a cooler wrapped really good and pulled them out 5 hours later steamin. Better to have it done than trying to rush it.... but.... lets say you find yourself with a butt at noon that is only hitting 175 and your starting to wonder if it will ever move again..... wrap it in foil and finish it in the oven set at 300 if you have to. I've done this in a pinch and it turned out excellent. Just make sure when you put it in the oven you wrap it in its juices and maybe add a little apple juice if it needs it.

At that size and using the 1.5 hours per pound, adding in another couple of hours for cushion plus a couple of hours rest time and you're looking at a start time of around 5:00 am.

Like FireItUp said, then if it gets done early, it'll keep hot for several hours well packed in a cooler.