you can do it in the morning and its over in about two hours from when you start.
the only change you might make is to add just a bit more salt than they call for. you dont want to absorb all that water or you will swell up like a toad. this can happen to people who are very dehydrated. btw, swelling of the legs is a sign of dehydration. and its usually not a lack of water but of salt.
try using up to half again as much salt as the recipe calls for. works like a charm.
i did a run for five days and got distracted. havent needed to do it again. after the butt pee stops be sure to drink plenty of water the rest of the day. wait as long as possible to eat and eat light as if breaking a fast, which is what you are doing.