[storyinmemo]

https://en.wikipedia.org/wiki/Watchclock

I found the pre-electronic way of having a portable audit clock that had keys attached to buildings with numbers that would stamp the clock rather fascinating.

[water-data-dude]

“This increase in the electronic systems led the largest U.S. manufacturer of watchclocks, Detex, to discontinue all of their mechanical watchclocks on December 31, 2011”

That’s a later date than I would have assumed

[gerikson]

It's weird that the Wiki article doesn't have an image of the actual clocks, only of the stations.

[shagie]

It appears to be rather unchanged since the earlier devices.

http://www.centraltimeclock.com/security/watchclock.php (the brochure and manuals are interesting)

And an old one ( https://youtu.be/xwkIzphNFZY - annoying music)

Clock with a rotating piece of paper in it. When the key is turned, it alters (cuts / stamps) the paper.

The modern ones are modern made, but the design remains rather unchanged.