I know the first week of leave we have (June starter here) is the 27th September - 7th October. The course is also 13 weeks long at a time, so I think the september course might be starting just after this if all of the dates are now delayed (we started on the 27th June instead of the 6th).
So week 13 for us ends on the 26th September. So the September course will probably do the induction week in Southampton in the week the rest of the course is on leave. Though, not a clue what will happen over Christmas....
H.