Clock: inserting leap second 23:59:60 UTC

Happy leap second, everyone. The earth's rotation slowed by another second, and the extra second was added just before the new year.

Or did it? According to the NIST "NOTE: No leap second will be added at the end of December 2007"

So why did some of my machines see one and some not? All are running NTP, all using pool.ntp.org. Perhaps some NTP servers in the pool falsely inserted a leap second?

According to this thread I'm not the only one to notice spurious leap seconds, one also happened in July 07, and this page documents one in July 06 with some great graphs.

Figuring out whodonit is tricky..

(Insert {conspiracy theory,thriller plot} here.)