The lapse "resulted in NIST UTC [universal coordinated time] being 4.8 microseconds slower than it should have been," NIST spokesperson Rebecca Jacobson said in an email.

That's just under 5 millionths of a second.

https://www.npr.org/2025/12/21/nx-s1-5651317/colorado-us-official-time-microseconds-nist-clocks