The target - as this season - is for all league fixtures to be completed by 31st August, with September for play-offs and remaining BSN and KO Cup fixtures. That would have been achieved this year but for rain-offs, eg Poole completed their league programme and then had to wait for others to sort their remaining fixtures out.
The big drawback to that is the same few successful clubs all meet each other in successive weeks in Sept/Oct.
So imo the BSN and/or KO Cup fixtures should all be completed by June/July. However priority was given to league fixtures being completed first......