musicmom

You could try a few things. Make his naps earlier in the day. I would only give him ONE nap and that would be around noon. Put him to bed a bit later.
Some tricks to help him sleep later would be to put a box fan in his room (it doesn't have to be blowing on him, it's just for the sound). You can also make his room dark(put a blanket over his window)use a very dim night light. Children can NOT get a good nights sleep with a bright room, some night lights are to bright.
If he starts sleeping later then you want him to sleep make sure you start to get him up at a regular time.
His little body will start to work on it's own clock.
I would start out with the first few nights doing a different routine. Keep him awake by playing. Then around 7pm I would give him a warm bath and read him a book and cuddle, maybe rocking him, also children sleep better with food in their tummy so a healthy snack could help. Then I would lay him down in his room with the noise of the box fan. If he cries, let him get himself to sleep (a child will usually not cry past 20 minutes) You can go in there and kiss him but do not pick him up and walk out (don't talk to him). He will get used to this within a few days to a week.

If your worried about him touching the box fan you can put up a baby gate in his doorway and put the fan outside the gate (you only want the noise)
The only downfall to the box fan is if you travel you may have to bring one with you because they will get use to the calming noise. Good luck.
I did this with all three of mine and they slept from 7pm to 7am. When they started to wake too early I cut out naps completly but that was when they were two.