I just got a new job (same company) after 17 years of 12 hour night shifts. The schedule is hell on family life and health.
My first systems job - mainframe operator - when I was 20 was three 12s nights then four days off. Switching between diurnal/nocturnal every week is hell, but I would cover other people’s days off, who then owed me shifts, so that I got an 11-day weekend every 2-3 months.
On Sunday mornings when everything was ‘done’, I’d kill time re-uniting people with their lost pets. The lost and found section would have 2-3 pets with both a lost and found notices, and I’d call the owners at 6am to tell ‘em.