slowly adjust the time....in the beginning you might need to 日夜顛倒 with your baby too...make him/her sleep earlier and earlier by a little bit everyday until his/her sleep time is back to normal...it's a long painful process...I hope you're still on mat leave right? Little baby's daily life is very routine and you can't change it all of a sudden.
﹐試過日頭同佢
﹐真係冇晒辦法