We are working on this now. Like PP, it depends on when he wakes up. Today we got up at 6:00am and he napped from 11:15 to 1:30. but most days he has been sleeping until 7:30, so he doesn't nap until 12:30 until 2:30.
One of my twins did at 10 months and the other at 11 months. At first, they slept from 11:00-ish until 1:00 or 2:00. Then they gradually went down later and later and now they go down at 1:00.
Re: From 2 naps to 1 nap