Extreme night shift work in high altitude astronomy is easily avoidable by using a split night shift where the first night shift starts before sunset and finishes at midnight and the second night shift starts with a new fresh person working through to after sunrise.

When your partner is regularly going out to bars and nightclubs and does not come home until after sunrise, it is likely that they are engaging in some form of infidelity.

I lost my circadian rhythm during extreme night shift work and I restored it by using continuous light therapy. I was waking up at sunrise with the birds, no alarm clock needed.

Continuous daytime full spectrum light therapy restored my circadian rhythm and I was waking up at sunrise with the birds.

If you are not naturally waking up at sunrise, then it is likely you have some form of Circadian Rhythm Disorder.