I would do 12:00. The timing of the nap seems to matter a bit less here these days. At home I do 5.5-6 A time, but nursery is more like 6.5-7. It seems more to be the formula of length of nap + night sleep is always the same. So a 2 hour nap, regardless of when it starts or finishes is a 10.5 hour night.
I am trying to do set bedtime at 7:30 these days. Not sure if it is working because he was very restless last night, but canines are coming through so hoping teeth rather than OT (one tiny corner of one darn canine so far....come on already!).