Just started (night 3) with a gro clock for our 2.5yo as she's suddenly started waking up the better part of an hour early and is clearly missing the sleep by the end of the day. It's set for the time she used to normally wake up. I'm not expecting miracles and am 50/50 whether she will get it, though she does tend to get things like this pleasantly biddable child sometimes! However while she gets that "blue means go to sleep", she seems a little vaguer on the concept of "waiting till its yellow sunshine to shout for mummy".
I'm guessing it is a week or two or going in in the mornings and pointing out that it isn't yellow sunshine yet. But any stories on how long it took a 2.5yo(ish) to get the concept?