My 4 month old started sleeping though the night when he was almost 3 months. Went to bed at 10:30 and I would wake him up at 7:00. We flew home for a visit at the first of the month which had a 3 hour time difference. He adjusted really well but when we came back 12 days later he wanted to go to bed much earlier and get up 2 or 3 times though the night screaming, like I have never heard before and wanted a bottle. As hard as I try I can't get him back on our routine. It has been 2weeks now. He has no problems falling asleep, he does rather well. I don't know if it is the time differance, a growth spurt, teething. I just don't know what to do???