[cdot2]

Julian date is sometimes used to synchronize timing for encrypted radio systems. My understanding is that early radio systems adapted it because it was used by astronomers. Astronomers used it because it didn't skip any days which would cause issues tracking long term astronomical cycles.

[iberator]

Julian date works exactly like Unix epoch, but instead of starting in junary 1 1970 it starts something like 2500 years ago.

Super easy for astronomy as you don't need to handle timezones and other junk

[Sharlin]

> Astronomers used it

And still use, in fact!

[cdot2]

I deal with those radio systems occasionally and I've always wanted to find or modify a digital watch to display the Julian date. It feels like that would be such a simple firmware change to something like a g-shock.

[jaywcarman]

Check out the Sensor Watch project[1]! It's "An ARM Cortex M0+ board swap for the classic Casio F-91W wristwatch" that allows you to write custom firmware.

[1]: https://www.sensorwatch.net/

[cdot2]

Thank you! That's exactly what I'm looking for.

[CodesInChaos]

The big annoyance with Julian days/dates is that they start at noon, not midnight.