Sunday, August 28, 2011

Time Zone support on iPhone

Okay, this is one place where the lovely "intuitiveness" of the iPhone falls right on its nose: time zone support.

I've had the pleasure of travelling from my normal haunts in the Central time zone to the Pacific time zone, but the displeasure of having all my appointments continue to show the appointment in Central time. For instance, an 8am meeting in Pacific time would still show up on the phone as being scheduled for 10am, which is the equivalent Central time (Pacific is UTC-8, Central is UTC-6).

The root cause of the problem is a setting I made in the "Mail, Contacts, Calendars" Settings page, not the "General" page--which is where the other time-related settings are done.

At the very bottom of the settings page (iOS 4), there's a section for adjusting calendar sync; it has a Time Zone Support submenu.

Setting Time Zone support on results in the phone "locking in" on the selected time zone--in my case, I set "Chicago" ages ago, when I first got my iPhone--and ignoring the "embedded" time in the calendars. There's an explanation on the submenu: Time Zone Support always shows event dates and times in the time zone selected for calendars. When off, events will display according to the time zone of your current location.


I'm not the only one with the misunderstanding. Google the phrase "iphone time zone problem," and you'll find a bunch of folks with similar problems: appointments set in one time zone will result in them "sticking" to the old time zone instead of moving to the new time zone with you.

Here's where the setting becomes counter-intuitive: If the device supports time zones, it implies that it "recognizes" that there are different time zones: an appointment set for 8am PDT should show up as 8am when the phone is in the Pacific Time Zone, while showing 10am when in the Central Time Zone. The opposite should also be true: disabling Time Zone support should result in the phone ignoring all time zone metadata and displaying all times as input, regardless of the physical location of the phone.

I don't have a problem with the iPhone operating this way; my objection is the way the settings are presented to the user. My recommendation is that the equivalent settings be duplicated on the General Settings page (Date/Time), and that the setting itself be called "Time Zone Override".


  1. I'm suffering from Timezone Support disease, and it's not as simple as the on/off toggle seeming to be the reverse of what's intuitive. ("Off" should mean it doesn't mess with your input, regardless of where you are.)

    I lived in Honolulu at the advent of "Time Zone Support", and now that I've moved to L.A., I find that when I change my timezone manually in my Mac, all my historical appointments (of which I'd like to have a record) shift forward three hours. Noon lunches seem to be at 3pm. The same thing happens if I try to turn Timezone support off altogether.

    I don't see a solution for keeping my old appointments properly situated except (and I'm not even sure about THIS) to keep timezone support ON, and keep the pulldown selection in my calendar permanently set to HONOLULU, regardless of the fact that I don't live there anymore.

    I'm not clear yet what would happen if, for example, TZS were ON on my Mac but OFF on my iPhone, or the reverse. The whole thing seems nutty. Why would anyone want their appointments to slip and slide in the calendar based on where in the world they happen to be on the day they look at the calendar? My appointment in NY at 2pm next week is at 2pm even if I'm thinking about it in L.A. the week before. I'm not "thinking" about it as if it's at 11am. I can think of no situation in which that really, truly makes any sense.

    Am I missing an easier fix than letting my computer believe it's permanently in Hawaii?

  2. Yeah, I missed my flight yesterday thanks to this wonderful innovation. If I tell my calendar that I have a 2:30 return flight from New York to Minneapolis, why exactly would I want my calendar to say that it's a 3:30 flight when I'm in New York? The only time I can think this would be useful is if I scheduled a conference call but then had a surprise trip to California on the day of the call. But flight times and other appointments don't change just because you traveled to a different time zone. In fact any face-to-face encounter is in absolute time not relative. A noon lunch is still a noon lunch... it doesn't change because I flew from Central to Eastern.

    Obviously I've taken some interest in this topic since yesterday. The instructions on the phone and on the Apple website are completely obtuse. In fact, as noted above, after reading the Apple instructions I was left with the impression that having the Time Zone Support off was the correct way to prevent this even though it was off and it still occurred. The above explanation was the best I've found on-line so I will turn the Time Zone Support on and hopefully I won't miss another flight.

  3. I wrote this for a friend and thought I would post it here in case it might help someone. There are 2 places in iphone Settings that affect time zone usage. This is how I do it…

    Settings>General>Date & Time
    Set Automatically = ON
    Time Zone =

    With the above settings, as you travel around, your iphone will automatically set the date, time, and time zone that you are currently in, assuming the mobile carrier passes it the correct information. There’s not much confusion here since it is similar to how all phones do it.

    Settings>Mail, Contacts, & Calendars>Time Zone Support
    Time Zone Support = ON
    Time Zone =

    The Time Zone Support setting seems to be a source of confusion. It has 2 parts.

    First, the “Time Zone Support = ON” setting will activate the time zone field when you enter calendar items. Let’s say you are currently in San Francisco. You want to enter a new calendar item for a 4pm meeting next Thursday when you will be in New York. When you are entering the event as a new calendar item, the time zone field will be available and you should set the time zone to New York (Eastern Time) and the time as 4pm.

    The second setting in Time Zone Support must be set manually. This controls in which time zone you will be viewing your calendar, regardless of where you are. Usually, you will set this time zone to be the same time zone you are physically in. That means when you view your calendar, all the times will be in your local time. Let’s say you are in San Francisco and you entered that 4pm New York meeting for next Thursday in your calendar. You have manually set the time zone in Time Zone Support to San Francisco because that is where you are at the moment. The 4pm meeting will show up in your calendar at 1pm since you are viewing your calendar in San Francisco time. Some people don’t like this, but I think it is correct. Let’s say you get sick and can’t fly to New York. You will dial into the meeting from San Francisco instead of attending it in person. At 1pm in San Francisco, the calendar alert pops up. You won’t miss the 4pm New York meeting.

    When would you want to set the time zone in Time Zone Support to be a different place than where you currently are? I live in Singapore and travel frequently to Europe and the US for work. Singapore is 12 hours ahead of New York. A 4pm meeting on a Thursday in New York will show up as a 4am meeting on Friday in Singapore. It can be confusing when I am trying to set up a bunch of meetings in NY. So, I temporarily and manually change the TZS’ time zone to NY when I am entering my multiple meetings. That way, I can see the correct time of day and the correct day of the week when setting up my meetings. I change it back to Singapore (or wherever I am at the moment) when I’m done.

  4. I don't understand any of this and I have a Ph.D.

    I want my clock to change with the time zones, but not my calendar. I want to set an event for 2 o'clock and have it always say 2:00 no matter where I happen to be located.

    If I am in Chicago and going to a play in New York the next day, and my friend in NYC asks me what time the play starts, I want to look at my calendar and see the correct 7:30 start time, not 6:30. How do I set my iphone that way?

    Only someone whose principal job is making scheduled calls would benefit from having the appointment times move every time you take a trip. And even, then, s/he would have trouble answering the simple question "What time is our conference call?"

    1. Don't quote me on this, but I think you have to turn Time Zone Support off for this to work for you. I had a similar problem. I had TZS set on. I scheduled a flight from Central to Pacific and put in return flight time (11:30) while I was in Central time. When I got to the Pacific time zone, the return flight time showed up as two hours earlier (9:30) than the actual flight time. I think if TZS had been off, it would have shown as the time I entered it (11:30), regardless of time zone.

      This would become a problem if I were traveling for work and had set a conference call time in my calendar with people from various time zones, then when I went to another time zone that time would be wrong since the times relative to GMT should remain the same.

      I think the only way this could be rectified is if there was an option to set TZS by appointment rather than overall.

  5. NEITHER state of this "time zone override" control will produce the result that so many (or even most) of us expect from a calendar alert. And Apple's description of this control is meaningless. The workaround described above, where you have to go into your time-zone settings and temporarily switch them to another time zone is ridiculous. Once again, Apple defaults to the most obscure case, instead of simply letting people OPT INTO this backward-ass behavior for special appointments like conference calls. This sums the asinine situation up:

  6. Amazingly, the new iOS still has a less than useless, time zone override. Whoever thought this was a good idea, obviously does not travel. Where were the adults when this brainchild was adopted?

  7. Thanks so much for this information. I have to let you know I concur on several of the points you make here and others may require some further review, but I can see your viewpoint.