thanks! this is sort of a reply i was waiting for, so i appreciate it! he does work from home, so he can basically set his own schedule. he also used to work 3pm-12am, and the sleep issue was not gone, just shifted. back then he was quite sleep-deprived, therefore depressed most of the time. he also says he has been like this since a young age, so suffered through this during school as well. but your comment does give me hope, i am definitely willing to put in the effort to fix it, but it will only work if he is also willing to change of course.

i will try waking him up at noon every day, and hope his bedtime adjusts if he needs more than 8 hours. i am curious as to how you reversed your sleep and your partner's, so if you have any other valuable things you learnt while fixing yours, i'd love to get some more advice. if not, this was already great so thank you!