I am sure someone on the forum can comment on this, but to be honest it really does not matter anymore.
Next June or so, the new Joint Commission recommendations must be in place, making a shift no longer than 16hrs for new interns. It is not an option, but a mandate. There is a slim chance the mandate will be modified or revoked, but not likely. As a result, all systems will have to go to a shift work or night float system. Senior residents can still take 30hr call, so that is what you will need to look at, NOT the intern schedules. A lot of programs will do away with overnight call all together.
Regardless, the schedules you see now on program websites and on this site are going to largely be changed to comply with the new Joint Commission standards.
Hope this helps.