I have a 12 month old who normally has a 1.5 hr nap in the morning, followed by a late nap (30-60mins) at 5. He's then in bed by 7.30/ 8. In the last couple of days he's failed to settle for his 5pm nap and I wonder whether it's because he no longer needs it. If so, is it possible to encourage him to sleep for longer in the middle of the day?