help me please !

i have a 1 month old baby who sleeps durning the day and is up all night 😩 or he will be up durning the day until night & go to sleep early morning like 6am so his schedule is all types of messed up soo my husband works from the evening and gets off at night so i have him most of the day until he gets off work .. so once my husband gets off and settle down he gets the baby .. he gets very frustrated with our baby where he will constantly complains about how the baby keeps him up and he wont stop crying and everything .. i’m just wondering is that a sign of postpartum? and what can i do to help my baby sleep better at night instead of being up all night ?