I would stick with the same naptime. There is some sleep research that discusses biological sleep times - times of the day when we are best able to sleep. I think it all ties in with circadian rhythms, etc. So I would go with the same bedtime. Stick with it for a while. Once it's established you can adjust a bit to cope with EW or OT. Am definitely not an expert as none of my boys have been great nappers, but I agree with the others in saying to just stick with set times for a while. You may want to check out Healthy Sleep Habits, Happy Child, Dr. Weissbluth. I don't agree with his sleep training advice, but the biology is explained a bit better there.