Lo is 14 months and one day I'll get a 1.5 hr nap this used to be a 2 hr nap and then every other day or so he wakes at 45 mins crying not really awake. I've been able to resettle him once but the other times no luck. I've notuced in on the days that he's woken early and I was trying a set time for nap at 1230. So usually he wakes at 730 nap from 1230-2 (5 hrs A time) then bed at 7-730. But on the days where he wakes at 7 sbd I try the nap at 1230 that's when I notice the short 45 min nap so I'm thinking ot? Can't think of what else it could be. Then we will do bedtime at 645-7 ish and then he just wakes the next morning 12 hrs of sleep at 645. Then we start the day earlier and end up with the same problem again. Maybe the set nap doesn't work for him and when he wakes at 645 his naps needs to be at 1145? Which makes lunch time so early. He's always got a tooth coming in lol. We just had 4 molars come through recently.
