I got a Mac Mini several years ago that came with Catalina. I hated the new look of Big Sur, so I never installed that. I now want to install a newer MacOS (Monterey), but initially and perhaps ...
I've noticed that when I go between OS X to windows and then back again on my box, that the clock invariably loses exactly 7 hours. Every time, exactly 7 hours as if it were in the wrong time zone.