Day/Night Cycle for PVE/PVP

My server is pve during the day with pvp zones and pvp server wide at night. Is it possible to make it where during the day it says PVE outside of a PVP zone but at night it says PVP no matter where you are? (Between certain times)

You can do this with the pvpall command.
What plugin do you use to switch PVP?