Don’t forget that night shift customer-facing jobs also have to deal with the night creatures that are said customers.
Things get real weird from 11PM-3AM. These people didn’t need IT support, they needed a psychiatric counseling hotline.
For me, my body literally couldn’t take the constant “biological darkness” (no UV). After three weeks, I experienced moderate dysphoria, anhedonia, and could no longer achieve restful sleep. Perhaps more-so than the average person, I am a slave to my circadian rhythms and absolutely depend on a normal clock to function.