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?