I normally put him down on the crib after being awake for ~1hr5min which gives him ~15min to fall asleep although usually, he closes his eyes within 5-10min after I put him down so that makes his S time ~1hr 10-1hr15min. Should I keep him up a little bit longer even if he starts yawning after only being awake for 40min? Also, sometimes, he doesn't go straight to sleep right away. He'll close his eyes within 5min of putting him down and then 5-10min later, he will open them or do a bit of mantra crying so sometimes, I don't think he goes to sleep right away.