Stuff like this has also been around for decades. Detex (https://en.wikipedia.org/wiki/Watchclock https://en.wikipedia.org/wiki/Watchclock) was a manufacturer o

Stuff like this has also been around for decades. Detex (https://en.wikipedia.org/wiki/Watchclock https://en.wikipedia.org/wiki/Watchclock) was a manufacturer of Watch clocks that used a key at the inspection stations to verify that someone had been to inspect that location at a certain point in time.