It may not be the kind of bug that wreaks havoc on your device, but sleepy Europeans might be cursing Apple’s name right about now: A long-standing bug in the iPhone’s alarm clock means many of them probably woke up an hour late on Monday.

AppleInsider is reporting that Europe’s switch to daylight saving time on Monday has caused many iPhone users there to sleep in an hour later, assuming they rely on their handset as their sole alarm clock. That’s because Apple has yet to fix a bug which causes the time not to update automatically, and therefore an alarm setting not to trigger when it’s supposed to.

"Both iPhones (3GS and 4) in my house failed to go off this morning," one AppleInsider reader reported to the website. "Even after checking and switching the settings in time/date and in the alarm app, there is still no alarm going off. Apparently this happened before. I had to delete all the alarms, restart my phone then re-set the alarms before they worked as expected."

While North America doesn’t recognize daylight savings time until Sunday, November 7, most countries in Europe do so on the last Sunday of October. You may recall hearing that the exact same bug tripped up iPhone users in both Australia and New Zealand in September, which caused their alarm clocks to go off one hour earlier -- which nobody would enjoy.

Apple has already ‘fessed up to the bug and a fix is planned for an upcoming software update, which could come with iOS 4.2 this month. Unfortunately, unless that update comes this week, it means that users here in the U.S. may suffer the same fate with their iPhone alarm clocks come Sunday.

If you rely solely on your iPhone as an alarm clock, we’d recommend an alternate for next Monday -- preferably something not running iOS, okay?

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