Thanks for the replies.
I'm still not sure I got the answer I was looking for or perhaps I didn't read the responses properly.
Lets assume that you are scheduled for 90 hours for a particular month(no sim or gs) and it turns out that your flight times ended up exactly as scheduled. Much of that flying is long haul where a portion of the flights will be spent resting which turns out to be 15 hours. Is that rest period part of the 90 hours you had scheduled.
I have been told by someone(which may very well be inaccurate) that your 90 scheduled hours didn't include the rest time.