Thread: Segmented sleep schedule + WBTB

So I have a polyphasic sleep schedule, more specifically the Dual Core schedule where I take a 3.5 hour core from 21:30 to 1:00, a 1.5 hour core from 5:00 to 6:30, and a 20 minute nap from 12:00 to 12:20. What I'm wondering is if it's possible for the second core nap to count as a WBTB, even though there's a four hour difference between the cores. If not, what would be the best way to get one?