The default behavior of many clock synchronization systems is to lurch the clock on a leap-second but for TimeKeeper, default behavior is few minutes of speeding up or slowing down the clock (slewing) in order to prevent failures. Lurching or “stepping” on most leap seconds involves repeating a second on the clock. A millisecond clock ticks 23:59:59.999…
You can see that Google starts its 20 hour leap-second “skew” 10 hours before the event and then skews back to the real time. Everyone else stays correct and then has a short error as they “leap” the second and then come back into correct time. A close look shows that a few minutes passed…
Leap seconds have caused tremendous problems with IT systems in the past. The last few 2015, 2012 and 2008, resulted in thousands of servers crashing across the internet leaving several sites (Foursquare, Yelp, LinkedIn, Gawker, Slashdot, Mozilla and Quantas Airlines) out of service for a while. Learn More
Leap seconds have caused tremendous problems with IT systems in the past. The last two, in 2012 and 2008 Download PDF