They will notify parents no later than January 1, 2014, whether the student is eligible to attend or whether there is no space for them.
They will notify parents no later than January 1, 2014, regarding* whether the student is eligible to attend or whether there is no space for them. (*or of)
The intended meaning of the sentence is to state what the parents will be notified about on January 1.
I confess I thought this was obvious until a mob of angry editors started getting all fired up about it. Now I must consider their very heated feelings on the matter (about a 50/50 split among them) & justify my choice. I am certainly willing to admit my take on it was wrong if that is proven to be the case, which is why I'm not divulging which I prefer or any of the arguments we've had over it.
Can anyone please, using grammar and logic, provide solid, rational reasoning I can lay out to the group for choosing one over the other?