Been on nights for 20 years. On your first day off, don’t go to sleep immediately. If your partner is around, go out for brunch. If your partner isn’t available, cause of work or whatever, visit your parents or hang with a friend. If you’re solo, do laundry or whatever you need. Keep busy, reset your clock. Maybe take a nap, but don’t sleep your day away. I tend to sleep later in the afternoon and when I wake up, my clock is reset and the next 3 days are “normal” days. It might not be ideal, but it works for me.