My son is in the transition from two to one nap a day. This means he usually takes one long nap in the morning and then an abbreviated one or just some down time in the afternoon.
On Thursday, I went to school for the graduation ceremony for the sixth graders, and then returned home to find that he had not slept in the morning. After feeding him lunch, I put him down, and he then had a long afternoon nap. Perhaps he is ready to start shifting the time more toward the middle of the day. This could be nice to regularize the summer activity schedule.
On the horizon is moving my daughter out of pull-ups at night. Who knows how this will go. Child development is so interesting even when seen from the trenches.