GMT Left By the Wayside as Atomic Time Takes Favour

By Sam Gibbs on at

Poor old Greenwich Mean Time might be out in the cold, if the UN has anything to say about it. They're looking to ditch the typically British time code, for a purely atomic time.

UTC, or 'Coordinated Universal Time', is currently based on GMT. The UN's ITU is discussing ditching the current system, which adjusts the incredibly accurate atomic clocks that keep time for the planet using leap seconds, to keep it in line with what humans experience -- solar time. The difference between atomic clocks and UTC is due to the planet's uneven rotation caused by reshaping of the landmass -- volcanos, earthquakes, that kind of thing.

Problem is, computers and anything that relies on precise timing, are thrown into disarray trying to cope with leap seconds, which are implemented every few years. Google for instance has had to come up with leap smearing to take care of it. This is a particular issue for GPS and other positional systems that rely on atomic time accuracy to give you a position fix and aren't exactly the most accessible things up there in space.

The ITU wants to essentially let atomic time go unadjusted, called UT1. People could then adjust their time accordingly, or not, depending on what function they need. The difference between UT1 and UTC would reach an hour in about 550 years, so it's not like it's going to rapidly accelerate away from us.

The ITU is waiting on replies on the issue from the 55 member states that control UTC, with 13 currently in favour and only three against. Honestly, this shouldn't make any difference to your average day. Perhaps, as The Register points out, we could do away with GMT altogether and just stick with BST for lighter evenings. But it does mean at some stage that your computer might be working on a different time than you are. And then there's battery life -- that's bound to start getting quoted in atomic time, just to sneak out a couple of extra seconds. [The Register, Wikipedia, Google]

Image credit: cybrain/Shutterstock