THOUSANDS OF IRISH PEOPLE woke up an hour late this morning – thanks to a glitch in the Apple iPhone’s alarm clock.

While the clocks of most iPhones are set by seeking the time from their mobile carrier’s network – meaning that Irish phones show the time as dictated by Vodafone, o2, Meteor or Three – it appears that the alarm clocks on the handsets are not quite so automated.

If you use the phone’s built-in alarm clock and have your alarm set to go off at the same time every morning, then it appears your alarm clock over-compensates for the clocks going back.

Oddly enough, this means that if your morning alarm is set for 7am, your phone – despite it reading ’7am’ on the display – will have actually gone off at 8am, a full 26 hours after the previous one.

It transpires that this glitch does not rectify itself if you merely de-activate your offending alarm, and then re-activate it: you’ll have to delete the alarm you’ve set and then create a new one.

Strangely, however, it would appear that Apple were fully aware of the glitch, which is apparently a new feature of iOS4 – similar problems were reported in the last six weeks when users in Australia and New Zealand started seeing their alarms go off an hour early when they introduced summer time.

At the time, Apple told ZDNet Australia that a solution to the bug had been identified and that it would be included in a future software update – but the solution, which would otherwise have been included in iOS 4.1.1, has yet to be deployed.