NIST warns several of its Internet Time Service servers may be inaccurate due to a power outage — Boulder servers 'no longer have an accurate time reference'

NIST has issued a warning that some of its Internet Time Service servers may be inaccurate due to a power outage affecting the primary atomic time scale in Boulder, Colorado. The outage disrupted operations, leading to a critical standby generator failure and an interruption in the atomic ensemble time scale. Specific servers affected include time-a.b.nist.gov to time-e-b.nist.gov and ntp-b.nist.gov, potentially providing incorrect time references. While the incident may not impact all NIST time services, users relying on hardcoded hostnames may face exposure to localized failures. The disruption caused a brief time drift of approximately four microseconds, with high-precision users like those in science or finance being alerted to monitor multiple time sources for accuracy.