Feeds

Boffins quarrel over ridding world of leap seconds

What should set the time - atomic watches or the sunrise?

High performance access to file storage

The measurement and regulation of time could start to change this week if an ITU meeting in Geneva, Switzerland, gives the nod.

International Telecommunication Union members are discussing whether Co-ordinated Universal Time (UTC) should be set using a system that does not factor in the Earth's imperfect spin – which necessitates the insertion of a leap second every so often so clocks can stay precisely synchronised with the world's uneven rotation.

UTC is based on the planet's revolutions and International Atomic Time (TAI), the latter of which is set by a network of 300 atomic clocks that don't lose track of time. The leap second was introduced in 1971 to keep the gap between the atomic clocks and the time according to the Earth's rotation at less than 0.9 seconds.

UTC was preferred over TAI as the standard time reference because it's more useful for mariners; it was believed a system that factored in the Earth's spin was needed for accurate navigation on the high seas.

However, some now say UTC will become unworkable because the planet's rotation is slowing down - meaning more leap seconds are needed. Other factors that can also affect the rotation include melting polar ice caps.

Steve Allen, of the Lick Observatory in Santa Cruz, California, has calculated UTC will require one leap second inserted per month by the year 3752. Back in the 21st century, leap seconds are inserted in December or June - the last leap second was added on 31 December, 2008, and the next is scheduled for 30 June this year.

Adding leap seconds poses technical challenges and potential dangers for systems that rely on time measurements, according to proponents of change: chiefly, servers, air traffic control, GPS and space missions. Software that relies on timestamps for transactions or for actions such as geo-location has to be updated to compensate for each change.

For instance, space agencies won't schedule lift-offs for days when leap seconds are added, and servers at Google apparently failed to handle a 2005 update. Google now runs the clocks on its computers slowly for a short period before an adjustment is due, ensuring the insertion of a leap second is a gradual process rather than an instantaneous one.

There are opponents to the potential change. Among them are ITU reps from Britain. Markus Kuhn, a computer scientist at the University of Cambridge and ITU member, has argued that there's a lack of credible evidence for serious problems caused by leap seconds, adding that computers can easily cope with leap seconds.

"We must not give up the >5,000 years old human practice of defining time through Earth's rotation because of unfounded worries of some air traffic control engineers," he wrote.

If the ITU agrees to remove leap seconds at this week's meeting it will be put to a vote at its next confab in September. ®

High performance access to file storage

More from The Register

next story
Video games make you NASTY AND VIOLENT
Especially if you are bad at them and keep losing
Russian deputy PM: 'We are coming to the Moon FOREVER'
Plans to annex Earth's satellite with permanent base by 2030
Solar-powered aircraft unveiled for round-the-world flight
It's going to be a slow and sleepy flight for the pilots
LOHAN's Punch and Judy show relaunches Thursday
Weather looking good for second pop at test flights
Honeybee boffin STINGS OWN WEDDING TACKLE... for SCIENCE
Not the worst place to be stung, says one man
India's GPS alternative launches second satellite
Closed satnav system due to have all seven birds aloft by 2016
Curiosity finds not-very-Australian-shaped rock on Mars
File under 'messianic pastries' and move on, people
Top Secret US payload launched into space successfully
Clandestine NRO spacecraft sets off on its unknown mission
prev story

Whitepapers

Mainstay ROI - Does application security pay?
In this whitepaper learn how you and your enterprise might benefit from better software security.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
3 Big data security analytics techniques
Applying these Big Data security analytics techniques can help you make your business safer by detecting attacks early, before significant damage is done.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Mobile application security study
Download this report to see the alarming realities regarding the sheer number of applications vulnerable to attack, as well as the most common and easily addressable vulnerability errors.