Could someeone who is advocating for no time zones please explain how a normal work "day" that crossed actual days work in practice? So you want to wake up at 8

Could someeone who is advocating for no time zones please explain how a normal work "day" that crossed actual days work in practice? So you want to wake up at 8 Utc and some else wakes up at 20 Utc. Ok, then they start work on Friday at 21 Utc and work until Sat 4:30. I'd imagine that you'd have to redefine weekend to mean Sun-Mon?