demerger

If the demerger proceeds in Feburary will the record date be set prior to or after the demerger.ie if one was to purchase shares next week will they definately be entitled to free shares in the new entity or is it possible the record date will preceed there entry date into mbi.
Just pondering the merrits of buying in or not anyone with more insight to this question please feel free to respond as I
do not realy understand how this all works.

regards

giordi0