Earlier quoted context omitted.
I was going to mention an Atomic Clock. I use one in an RV and it sets itself even outside of cell phone range. I know it uses a radio signal of some type but I have no idea how it works. It rights itself within a few minutes of time changes, battery loss, or the like.
It's fascinating reading if you're interested in finding out the details: https://en.wikipedia.org/wiki/WWV_(radio_station)
https://news.ycombinator.com/item?id=46952384
https://github.com/tanvach/clocksync
https://github.com/kangtastic/timestation
https://github.com/hzeller/txtempus
WVB: A Tiny WWVB Station - https://news.ycombinator.com/item?id=13258631 - December 2016 (49 comments)
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