For the PM's out there
Duration: 1 hour
Pred: 23FS - 1h
Duration: 1 hour
Pred: 23FF
should both start and end at the same time (that is start 1 hour before 23 ends and finishes when 23 ends)
I'm not missing something there, am I?
While the first is allowed, perhaps it should not be as that invalidates the "predecessor must finish before I can start".
Craig