DNS migration of time.nist.gov

[jeff.s...@nist.gov]

Hello,

NIST is planning a change in the domain name system (DNS) implementation of the time.nist.gov domain name. Work to implement the change is scheduled to occur approximately between Monday, Oct 20 2025 7:00 EDT and Wednesday, Oct 22 2025 9:00 EDT.

Due to the distributed, hierarchical, and cached nature of DNS, software clients using time.nist.gov may experience a longer outage, transient- or otherwise unexpected behavior, DNSSEC validation errors, etc.

Clients making use of NIST time servers' individual domain names or addresses (https://tf.nist.gov/tf-cgi/servers.cgi) should be unaffected.

After the change, the intention is that time.nist.gov will still dynamically resolve to a random (recently tested as healthy) NIST time server address with the goal of distributing client use more evenly over available servers.

Best wishes,
-Jeff A. Sherman
Project email: internet-t...@nist.gov