Day/Night Reversal?! 😩Suggestions?

So my little guy has his days and nights totally mixed up. From 12am-5am he is UP! And typically pretty fussy too. But then from about 5:30am-7am, 8am-10am, and 11am-1pm he’ll sleep. We keep day time light and there’s lot of noise and typically visitors of some kind too. And night time is quiet with dim lighting and calm music. So far no luck (this is not to mention that we still can’t get him to sleep in his bassinet.

He’s 3 weeks old, any suggestions?