I would probably do a breakfast, lunch, dinner type of routine with hours like that. When do you get up? I would feed the puppy right when one of you gets up so there's time to let it out. Then again when your wife gets home, and then again around dinner time. That would give enough time for the puppy to go potty after meals and then probably potty again before going to bed yet not be too hungry over night.
An 8 wk old should eat 3 times a day, so I'd say feed the pup as early as you can so he can poop before you leave for work, then he can eat lunch when your wife gets home and dinner about 6 so there's plenty of time to go our before bedtime. You'll get used to how long it takes between eating and pooping.