This year my country decided we no longer needed summer saving time, and since the date when time was supposed to change to summer time, my iPhone has had the wrong time.

I have an iPhone 4. I believe newer phones don't have this problem.

My phone thinks it is summer time and is 1 hour off if I set it to synchronize automatically. I resorted to somewhat convoluted tricks to keep it synchronized correctly. If I fixed the offset time manually, Whatsapp went wrong.

How is it possible? What does it do when I set the time to synchronize automatically? I previously thought it synchornized with the phone service provider but it appears to not be the case.

1 Answer 1


The phone receives the current time in UTC from the carrier (or from NTP server) and applies current timezone adjustment based on your settings. I assume that the timezone data in your phone is probably outdated and reflects the old rules of applying DST, that's why you have 1 hour difference.

  • What about older phones? Old phones before the smartphone era got the time right every time and I don't think they knew anything about timezones. If they receive the time in UTC from the carrier, how do they know what timezone they are in?
    – José
    Dec 3, 2015 at 23:50
  • I don't remember the phone old enough that could receive the time from the carrier but did not have time zone setting. Maybe they existed, but I just didn't see them. I remember the phones with timezone setting that couldn't receive the time from the carrier though.
    – Paul
    Dec 4, 2015 at 2:48

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