And yet, not everyone requires this. It really depends how well prepared everyone is going into the project.
For example, my band (before I was a member) recorded our first CD in two 8-9 hour sessions. There are only 8 tracks and the album turned out to be 26 minutes long, but it was a remarkable job given the amount of recording time taken. One of my favorite songs from the album was the one and only take.
(Random aside, I'm wondering what members of the board would say about the job the engineer/mixer/ME did on the album, but I don't know the best way to post it without 'giving' it away. Any ideas? I'll be engineering our next album, but I want to know if we should take it to him or go somewhere else.)