As far as the JAA questions are concerned, it has to do with when you pass 30W; you may in in the OTS (within prescribed times), outside the OTS (withing 1 hour (???) before/after the start/end of the prescribed times), or in random airspace (other hours).
Now for all practical purposes... the difference between "outside OTS" and random airspace... That's an entirely different question. But that's the JAA for you anyways :-)