Remember the Y2K bug? In the years prior to January 1, 2000, computer scientists, politicians and conspiracy theorists (I believe the last two are becoming redundant) predicted chaos, mayhem and possibly the end of life as we know it when computer programs that dropped the ‘19’ in records storing the year were forced to deal with the ‘00’ of 2000. Nothing seriously bad seemed to happen then, but those same doomsayers are saying doom to the upcoming leap second on June 30, 2015. Should we be afraid?
A “leap second” is needed because the Earth’s rotation slows down by about two thousandths of a second every day but Coordinated Universal Time (UTC) and the Network Time Protocol (NTP) used by the Internet and local area networks are not adjusting automatically. We’ve had 25 leap seconds since 1972 with the last one occurring on June 30, 2012. That’s part of the problem. Leap years are regularly scheduled while leap seconds only occur as needed and are sometimes on June 30 and other years on December 31.
When a leap second is scheduled, computer networks using NTP are notified to be ready for receiving the additional second in the sequence 23:59:59, 23:59:60, 00:00:00. This caused reported problems in 2012 for some companies including reddit, Mozilla, LinkedIn and many running Linux. Few specifics were released by the companies although Qantas Airways admitted its computers crashed.
Google avoids the whole leap second problem by using doing what it calls a “leap smear” – gradually adding milliseconds to its system clocks prior to the leap second. This means Google’s clocks are slightly faster than everyone else’s – is that smart or evil?
So, should we fear the leaper? It seems like no one knows for sure. Those who support the Linux and Unix kernels say these operating systems are ready for the leap – but that’s what they said in 2012. The leap second is five-and-a-half months away so IT departments and network administrators should have plenty of time to install a fix – but that’s what they said in 1999. The International Telecommunications Union, the group responsible for UTC, is considering dropping the leap second entirely – but its next meeting isn’t until November.
Sounds like a lot of uncertainty. Should we be worried?