It's hard to have a good time on a Mac

Horology is hard. It's even harder on a Mac. Yes, even the $7000 Mac Pro.

Resources mentioned and products referenced in this video (some links are affiliate links):

- Blog post with all the gory details: https://www.jeffgeerling.com/blog/2025/using-gps-most-accurate-time-possible-on-mac
- The USB GPS module I was using: https://amzn.to/4j08we1
- Decent little GPS antenna with U.FL adapter: https://amzn.to/43dxctt
- NIST-F4 Clock video: https://www.youtube.com/watch?v=CYpBaUgxGl4
- ChronyControl: https://www.whatroute.net/chronycontrol.html
- GPSDConfig: https://www.whatroute.net/gpsdconfig.html
- Precision Clock by mitxela: https://www.youtube.com/watch?v=SNqm5T5syTM

Support me on Patreon: https://www.patreon.com/geerlingguy
Sponsor me on GitHub: https://github.com/sponsors/geerlingguy
Merch: https://www.redshirtjeff.com
2nd Channel: https://www.youtube.com/@GeerlingEngineering
3rd Channel: https://www.youtube.com/@Level2Jeff

Contents:

00:00 - Horology is hard on a Mac
01:04 - It's easier on a Pi, and better on a Watch
02:07 - GPS works on a Mac
03:44 - It's time to go mobile
04:21 - PyGPSClient and GPSd
08:01 - ChronyControl and time sources
09:20 - Getting time from GPSDConfig
10:47 - We have time (offset)
11:54 - Tracking time
13:27 - What's the point?