My DD is 11 months, and just this past week transitioned from two naps to one, but she's also going to bed earlier.
She used to wake up around 6-630, and take a nap around 9/930 for about an hour and a half (usually). Then she'd have another around 2/230 for about an hour, and go to sleep at 8/830.
But the past couple weeks, she's shortened the morning nap to an hour or less, she'd fight the afternoon nap, end up not taking it until 4-5, and be up until 9pm+.
So, the past couple of days, I've been coaxing her to stay up in the morning until 1030/1100, and she's gone down with no protest (knock on wood) for 2.5-3 hours, and now goes to bed at 7pm (still waking up around 6-630). She's been MUCH happier lately, and I really enjoy the longer break, which gives me time to get stuff done.