Ok so I know this isn't as bad as all the other things I've heard on here but.....
I have an 8.5 month old daughter, she pretty much sleeps through now (occasionally needing re-settling, obviously all goes wrong when teething etc!) but she nearly always wakes up at 5-5.30. She doesn't wake up hungry at all. She'll go to at least 6.30-7 before wanting breakfast so that's obviously bot why she's waking up! Why, why, why?! This week she has also completely changed when she has her naps and for how long! She has been miserable the last couple of days and I am convinced it's because she is tired but I don't know what to do about it!
Sorry - I have no magic answers. DS went through these phases of waking early - we had to ride them out and make sure he got an early nap in the morning to see him through the day plus put him to bed a bit earlier.
Sometimes. Even now at 21 months it helps. I do it because he gets so grumpy otherwise. Plus around 8/9 months he went from 3 to 2 naps a day which meant he needed to catch up a bit on sleep so needed an earlier bedtime otherwise it got harder and harder to settle him. Even as little as ten minutes made a difference.