How To Work Around The iPhone 4 Daylight Saving Alarm Bug

We noted the importance of checking the time on devices when daylight saving began over the weekend in many states, but it turns out that iPhones running iOS 4 have a more subtle problem: recurring alarms go off at the wrong time once daylight saving has kicked in.

Numerous reports on Twitter and discussion forums attest to the problem, which first became evident last week in New Zealand, where the switch daylight saving happens a week ahead of Australia). The issue purely applies to recurring alarms (such setting an alarm for the same time every day to wake you up for work). The effect varies depending on when the alarm was created, according to one poster on Apple's own support forums:

Recurring alarms that were set prior to the Daylight Saving switch went off an hour later than intended. Recurring alarms that have been set since Daylight Saving began, go off one hour earlier than the time they are set for.

Even users in states where daylight saving doesn't apply have reported problems, so anyone using an iOS 4 device needs to be cautious. (Reports suggest there's no issues with the older iPhone 3 releases unless they've been upgraded.)

Until Apple issues a patch, the easiest way to avoid the problem appears to be setting individual one-off alarms, rather than recurring ones. Problems with daylight saving are hardly unknown, but let's hope Apple does a better job of managing it in future.



    My girlfriend's iPhone 3G with iOS 4 on it had the alarms go off early. After the clocks all reset to daylight saving (we're in Brisbane - no DST here) yesterday morning, we eventually managed to reset them to the correct time zone, the alarms then went off an hour early. They were set for 6am, but they went off when the time on the phone was at 5am. We deleted and re-set the alarms and they look to be okay now..........

      I do the same but does't work for me, it s the software of iPhone 4 -problem. I could not believe that apple expert did not check OS before release for public use.

    What about places where daylight savings doesn't apply? (ie. Perth, WA.)

      It --seems-- to be an issue for anyone in an Australian location, regardless of DST -- the impact might differ but it's definitely worth checking.

        cheers! will post if anything interesting pops up.

    Or if alarms set now are guaranteed to go off an hour earlier, you could just set them for an hour later so that they go off at the actual intended time.

    Yes this one got me this morning (4:50am alarm instead of 5:50am!) and I did a bunch of testing to work out how to get around the errors. Using one-off alarms look to be the only way.
    NZ suffered it last weekend.

      I was having the same problem with my alarm going off an hour early, I have since turned off the autolock & it now works fine

    This doesn't seem to affect me (iPhone 4 on iOS 4.0.1)

    Just set a recurring alarm and it went off fine.
    3GS on 4.0.1

    Same issue for myself. What I did was to update your time, followed by deleting your existing alarm setting and recreating it again.

    BAHAHAHAHAHA, even my old Nokia dumbphone (b/w screen) could handle daylight savings.

    Neither my HTC Desire, nor my wife's iPhone 3 updated (we're in NSW). We both had to reboot our phones to force an update (? Telstra's fault).

    We're iPhone/iPad developers (, so we have been playing with all sorts of stuff in the iOS for some time now.

    Although it's hard to tell exactly what's going on at an OS level, my suspicion is that the alarms actually are handled as "countdowns" by the phone - so when the automatic time-setting changes, the amount of time left on the "countdown" is actually wrong and unpredictable results happen (early/late/dead alarms).

    My 3GS and my wife's iPhone 4 both with iOS 4.1 simply "forgot" to go off on Sunday morning. We're in Brisbane, but had been set to "auto" and the Optus network apparently can't tell the difference between Canberra and Brisbane (I'm happy to say that there is a BIG difference :-)

    Once we reset the time to "manual", selected the region, and changed back over to "auto", all was fine.

    No probs with early/late/dead alarms since.

    Also try toggling the on/off state of any recurring alarms you may have. Seems to help (lending more credence to the "countdown" theory).

    My iPhone 4 (on 4.0) seemed to work correctly this morning. Unfortunately I didn't need it to go off!

    And I thought someone was playing a joke on me this morning when my alarm went off an hour early... Thanks Steve!

    I just can't understand how, with so many constant problems, ppl are ok with the higher prices apple charge over their competitors.. It's just getting stupid.

    I'm from Sydney, just got my iPhone 4 few days ago. I've an alarm set at 7:30am and man, I went off at 6:30 !! At first I though I see it wrongly, but it's two days in a row now, it ruin my holiday.

    I tried all the above but recurring alarm just won't go off.

    Lol at the 3AW rantings this morning :D

    I'm in Sydney and my iPhone 4 with iOS 4.1 went off 1 hour earlier this morning too. But this happened to recurring alarm, one-off one was ok.

    I have a workaround that works for me.
    1. Go to Settings > General > Date & Time
    2. Switch off Set Automatically.
    3. Set Time Zone to Brisbane (which DOES NOT have Daylight Savings)
    4. Set Date & Time to the local date/time

    After that, the recurring alarm goes off correctly.

      Thankyou it seems to work so far but let's see in the morning if it again wakes me at 4am instead of 5am

    Changed time from auto to man, selected time zone and all was fine for yesterday, now I get woken up early again this morning! Apple need to fix this now.

    Don't blame it on Apple, I think it's something to do with the telco's side of things if your phone's set to auto time


    It is definately Apple's issue. There may be some issues with the telco's setting of the time on your phone if you're in QLD or WA, but if my alarm says 6:30 and it goes off when my phone says it's 5:30 then it's a phone issue.
    Blame Apple! Blame Apple! Blame Apple!

    Ben2 ... that only works for general, one off alarms.

    Try that for (say) weekdays only and it doesn't work.

    Thanks this works.
    October 5, 2010 at 8:52 AM
    I have a workaround that works for me.
    1. Go to Settings > General > Date & Time
    2. Switch off Set Automatically.
    3. Set Time Zone to Brisbane (which DOES NOT have Daylight Savings)
    4. Set Date & Time to the local date/time

    After that, the recurring alarm goes off correctly.

    also check when your last update to your email is too via in yr iphone! that's also outta wack!

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