Zombie time = weekends and weekdays between 3pm and 7pm.
The times when zombies walk the earth, pushing trolleys around without taking any notice of anyone else there, shoving the things into the back of your legs etc without taking a blind bit of notice, clogging up the place, leaving the things in the middle of the aisle or totally across a section of shelving blocking it from others, "excuse me" is a alien word to the zombies, it is met merely by a blank look.
They are totally unaware of their surroundings even without the trolley they are hitting people and things with their bags and repeatedly stepping backwards without looking.
Can they have their own supermarket please we can call it Zombie Mart or something.