I picked up the 3rd edition of Daniels Running Formula. He now includes a dedicated plan for the half marathon, and during phase 3 consistently schedules back to back quality days for Wednesday and Thursday. Usually they are something like 3 min Hard/Interval repeats on the Wednesday, then Tempo mile repeats on the Thursday.
Now I find this a bit odd as he stressed in Program A for the Marathon in the 2nd edition always take 2 days between quality sessions - granted, the Hard sessions are not as demanding as some of the I sessions in that plan (5x5 Minutes Hard etc.), but the tempo ones are very similar.
Does any one have any insight in to why the plan is structured like this? And not, for example, Hard/Intervals Tuesday and Tempo Friday, as per the "Running for fitness" plans he includes? The only thing I can think of is that there are occasional M pace runs on Sunday, so wants runners to be rested for these.