So, what would happen when going for a new season?

I mean, how will it happen? Is it like, the same old usual "Patch pvp will be shutdown for next season patch. The server is estimated to be unavailable for 6 hours" then after that the usual update? Or does it happens by shutting down, and then wait like a day or 2 then the update starts?

Sorry, I joined league like a few weeks after the start of season 4, so I'm not sure how this one goes.