C.W.
My granddaughter who is 26 months now used to take two naps a day and we just had to result to one nap when she was 18 months old , so now she only takes a nap around 1130 or 12 noon and is up by no later then 2pm and is down for the night around 7-8 pm . The trick is to keep them busy in the morning to keep them up longer in the mornings. However, we do miss the two naps since WE had more time to do things while she was asleep. She is doing well with the schedule change and it took a couple of days to get used to.
Good luck
C.