7 month old disrupted sleep schedule.

Hannah • Hey my name is Hannah. I am a 27 yo SAHM 💙👶🏻 💙4/29/16 💙👶🏻 💙4/23/18
So my son has been sleeping through the night since he was 3 months. My SO has switched to the night shift from 4-12am and gets home at 1-2am. My son has completely reverted in his sleep schedule. He is up he wants to play and eat and this happened at the same time of the switch. Does anyone have any recommendations that we can get him to sleep through the night?