As NSW, Victoria, Tasmania, the ACT and South Australia switched to daylight saving time at the weekend, a bug in the Apple iPhone caused some workers to run late yesterday.

The bug appears to affect only those with a "recurring" alarm, which is useful for when you want to be woken up at the same time each and every day of the week.

Online forums were filled with Australians discovering the bug; they have found a simple fix - to set their alarms one hour late. Setting a manual alarm each day - instead of having it occur automatically - was also said to work, Macworld said.

Some users said their iPhone alarms did not go off at all.

There has been no indication when a fix might be made available. Apple Australia has been contacted for comment but is yet to respond.