June 30 Leap Second Worries Markets, Internet

(Photo credit: @Doug88888, used under CC BY-NC-SA 2.0 license.)

The coming leap second on June 30 sounds as scary as the (turns out not-so-scary) Y2K bug. But the world has experienced leap second issues before, and most affected industries are taking steps to prepare.

The world’s clocks will be adjusted by one second on June 30, when a leap second will be inserted into Coordinated Universal Time (UTC), the standard international time scale. In theory, all UTC clocks should insert a second labeled 23h 59m 60s (the leap second) following one labeled 23h 59m 59s UTC. This is equivalent to having all of the clocks in the world stop for one second at that time, as explained in May’s Expert Advice column.

A problem with some GPS receivers implementing the extra second caused the U.S. Civil GPS Service Interface Committee (CGSIC) to issue a notice in February. But GPS receivers aren’t the only thing that could be affected.

The Wall Street Journal is reporting that financial regulators and market participants are worried enough about the leap second that they’re planning for potential disruptions. The adjustment could present technical difficulties for traders and exchanges, as some computers might not be programmed to account for the adjustment, according to a Dow Jones report.

“These guys are agonizing over it,” Steve Allen, a programmer-analyst at the University of California’s Lick Observatory, told Dow Jones. “It is definitely a hassle.”

“The problem with the extra second is that it’s difficult to gauge how computer systems will react,” according to Journal writer Brian Hershberg.

A U.S. Commodity Futures Trading Commission spokeswoman said that “For the most part, we’re not too worried,” told Dow Jones. “But of course as the regulator, we do need to ensure folks are ready.”

The last leap second occurred on June 30, 2012, and that leap second caused technical problems for websites and computing systems — including Reddit, Mozilla, Gawker, FourSquare, Yelp and LinkedIn.

Google had prepared ahead of time and was unaffected. Google gradually adds a couple of milliseconds to its servers’ clocks throughout the day when a leap second is to occur. According to a 2011 Google blog, “We modified our internal NTP servers to gradually add a couple of milliseconds to every update, varying over a time window before the moment when the leap second actually happens. This meant that when it became time to add an extra second at midnight, our clocks had already taken this into account, by skewing the time over the course of the day.”

But many web services didn’t follow Google’s lead in 2012 and experienced disruptions. Qantas‘ computer system went down for hours, forcing employees to check in passengers by hand. For background on the 2012 event, and a good explanation on the reason for a leap second, read “Time to Get in Sync” by Richard Langley, GPS World Innovation editor.

Amazon Web Services said it plans to “implement alternative solutions to avoid the ‘:60’ leap second. This means that AWS clocks will be slightly different from the standard civil time for a short period of time.”

In the U.S., stock exchanges such as the New York Stock Exchange and Nasdaq are working around the leap-second time (8 p.m. in the U.S.) by closing its after-hours trading a half-hour early, which is scheduled for 8 p.m.

The Hong Kong Observatory is advising stakeholders and operators in information technology, telecommunication, transport, and finance to review whether systems under their management can handle leap seconds properly, and if necessary, consider testing and adjusting their systems to ensure normal operation during and after the introduction of the leap second.

Time and frequency company EndRun Technologies is offering leap-second information on its website, and Cisco is offering its customers guidance on how to deal with it.

Racelogic, who make the LabSat simulator, will be recording the Leap Second as it happens and will then have the scenarios available for customers to replay. A variety of recordings will be taken: GPS, GLONASS, and BeiDou constellations will each be captured as a single channel, and also as a simultaneous triple-constellation recording. These will then be available to use with the LabSat.