It is hard with daylight savings. I just keep to the normal times. SO 8pm is bed time regardless of light/dark. We have block out blinds too but still a bit of light comes out the top. So for the past few weeks I have kept to this routine and it can take up to an hour to get them to sleep but the more they are getting used to it the more they are going to bed closer to 8. I have a 3.5 year old and a 23 month old. The older one hasnt had a sleep since abut 21 months and the younger one is in the middle of dropping hers. I would be inclined to just stick with your bedtime routine and you wll find that he will adjust (sorry this is all over the place) in a few weeks. You just have to try and be consistant with it.