The National Institute of Standards and Technology has warned that several of its Internet Time Service servers could be providing inaccurate time following a failure of the primary atomic time scale, NIST-F4, at its Boulder, Colorado campus. The alert was posted to NIST’s public Internet Time Service mailing list after a prolonged utility power outage disrupted the facility on December 17, with engineers still working to fully restore normal operations several days later.
According to NIST, the Boulder campus lost utility power at approximately 22:23 UTC during a period of high winds that triggered line damage and preemptive shutdowns tied to wildfire risk in the region. While backup systems were expected to maintain continuity, NIST says a critical standby generator failure occurred downstream of the signal distribution chain that feeds its Boulder-based Internet Time Service infrastructure. As a result, the atomic ensemble time scale that underpins those services was interrupted.
