Around 15 1/2 months, Duke officially dropped the morning nap. I'm planning on doing a detailed post about how that process went for us. His afternoon nap begins at 1:00 and lasts until 4:00-4:30. Teething has caused a few naps to end closer to 3:45. His night sleep falls anywhere in the range of 12-13.5 hours, but 13 hours is the average.