How long would it take to watch all 6 Star Wars movies in one day/night?

This Friday night, me and a few friends are going to try to pull an all-nighter and watch all 6 Star Wars movies in one night.

How long would this take?

Which versions should we watch, the original movie ones or the extended ones?

Which order to watch them in, the way they were released or in the intended sequence?

Anyone here ever done it before?