I started turning my lights back on some of my racks around August - I just try to follow the actual change in day length, and move my timers back/forward when I notice the days getting longer/shorter. Worrying about my electrical bill helps, too.
Unless it's outside, I doubt you'll see much in the way of dormancy for your Ceph. They just slow down, and sometimes grow those non-pitcher winter leaves. If you're lucky, you might get the weird vestigial not-a-pitcher, not-a-leaf leaves. I usually do about 12/12 for my Neps, Ceph and Helis. During the summer I'll split the 12 hours with the lights on into two parts, so that the lights aren't on during the hottest part of the day. I don't think it matters a whole lot unless you're trying for flowers.
~Joe