ntpsec.anastrophe.com

ntpsec.anastrophe.com

Access policy: Syncing more frequently than once every THIRTY minutes will result in your connections being blocked. If your clock drifts so much that you think you need to sync every one minute, five minutes, fifteen minutes - then that's a you problem, not a me problem. Commercial use is prohibited. Contact me at ntp@anastrophe.com if you wish to make other arrangements.

NTP and SNTP service is available on port 123. Sorry, no IPv6 nonsense for here.
NTS service is available on port 4460. Use domain name nts.anastrophe.com.

You can verify the NTS cert here: What's my chain cert
And third-party verification of the time is here: Web Wiz NTP server test tool

ntpviz generator (this server):
- Raspberry Pi 4 Model B Rev 1.5, 4gb ram
- OS: Debian 13.x - Trixie
- Webserver: NGINX
- Monitoring: Monit (highly recommended)
- Roughly 5 minutes once per hour to generate all graphs

A portion of the journey here: (outdated), and a more recent configuration (now only one timeserver).

ADS-B - Flight Tracking For Fun And No Profit

a-ntpsec.anastrophe.com

Refclock: uBlox Neo m8t HAT on a Raspberry Pi 3 Model B+ Rev 1.3
OS: Debian 13.x - Trixie
Time sync: gpsd 3.27.5 and ntpsec-1.2.4

All graphs generated with ntpviz.

Many (most?) elements shamelessly cadged from Royce Williams' most excellent NTP resource site.

This site tests "A+" on the Qualys SSL Labs Server Test page.