time.lettersblogatory.com

the Letters Blogatory time server

time.lettersblogatory.com is a free service that you can use as a source of time to help set the clock on your computer. It uses the Network Time Protocol and aims to be an accurate and secure source of time. This page describes the service and how you can use it.

Description of the service

time.lettersblogatory.com is a stratum 2 NTP service. It sets its own clock using time provided via NTS by well-known stratum 1 NTP servers, which obtain their time from atomic clocks and satellite signals. These servers are ptbtime{1, 2, 3}.ptb.de, of the Physikalisch-Technische Bundesanstalt, and ntppool{1, 2}.time.nl, at SIDN Labs. The time.lettersblogatory.com server is located in the Netherlands. You can access it either over IPv4 or IPv6.

The server uses chrony 4.3 on Debian 12.10. It runs on an Akamai VPS.

Accuracy

You can see data about the offset of the server from its stratum 1 source, and the root delay and dispersion, for the past week by clicking here. The NTP Pool Project also keeps statistics for my server over IPv4 and IPv6. Future performance may differ from these statistics.

Terms of use

Use of time.lettersblogatory.com is subject to the following terms of use.

1. You can query the time.lettersblogatory.com server using NTP with or without NTS.
2. My server is an open access server, which means:
   • You may use iburst, but not burst,
   • You may not change minpoll to a number below 64s or maxpoll to a number above 1024s,
   • Your software must honor a KOD message, and
   • You must not hard-code my server's domain name or IP address into any hardware, firmware, or software.
   In addition, you should use pool.ntp.org or a suitable list of time servers rather than a single server.
3. The following activities are prohibited:
   • flooding or abusive querying that exceeds reasonable limits,
   • security attacks such as spoofing, amplification, or DDoS-related activities.
4. I reserve the right to block any IP address from querying the server for any reason, and the right to discontinue the service at any time.

No promises

I’ve set up this service as a personal project in order to learn more about how computers synchronize their clocks, and for fun. I try to make it as secure and reliable as I can. But it is a free service, and I offer it “as-is,” and without warranties of any kind. I disclaim all implied warranties to the maximum extent permitted by law, including warranties of merchantability, warranties of fitness for a particular purpose, and warranties against infringement, and I do not make any promises about accuracy or availability. I reserve the right to stop offering the service at any time and for any reason. If you need a source of time that comes with guarantees about accuracy or availability, you should consider commercial alternatives.

Security

My service supports Network Time Security, or NTS. NTS allows you to authenticate the time you get from time.lettersblogatory.com cryptographically. Consult the documentation for your NTP software for how to configure it to use NTS.

Data privacy

I take data privacy very seriously. This service does not log requests and in particular does not log the IP address or any other personally identifying information regarding requests to the server.