Last reviewed on June 18, 2013   —  34 Comments


When I send or receive meeting requests or view other people’s calendars, the appointments are off by one hour.

This is caused by incorrect time or time zone settings on one of the computers.

1. Verify all computers involved are set to the correct time, time zone and daylight savings time settings in Windows Control Panel’s Date and Time applet. You can open the Date and Time applet by double clicking on the time in the system tray.

2. Verify the settings are also correct in Outlook. Tools, Options, Preferences tab, Calendar Options button, Time Zone button.

If you are using Outlook 2010 you need to use a time zone with the correct DST settings for your location. If your location does not observe DST, do not choose a time zone that does then deselect the option to automatically update for daylight saving time. You need to use a time zone that does not observe DST.

In Outlook 2007 and Outlook 2010, if you receive an iCalendar that does not include time zone offsets in the ical, Outlook may place the appointment on your calendar using standard time, not current time. For example, if you subscribe to an Internet calendar that does not include DST information, Outlook will treat the events as referencing standard time and move them ahead an hour if they occur when DST is in effect. As a result, an appointment scheduled for noon will be on the calendar at 1 PM.

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  1. Raj says

    how to sync daylight saving between to countries, for example between an US client and Indian client..?

    • Diane Poremsky says

      There shouldn't be anything to sync - if both the sender and recipient use the correct time zones for their locations the the meetings will adjust for the correct local time in each time zone. The big thing to remember with Outlook 2010 especially, is that it uses the underlying time zone and if someone sets windows to use a time zone that honors DST but disables the automatically adjust for DST option, Outlook will still apply DST to the appointments. You need to use the correct time zone offset for your location.

  2. Chris Bedford says

    Is it too late to re-open this topic? It doesn't seem this issue has been resolved...

    I have a user with a MacBook Pro using Mountain Lion and iCal. He has been sending meeting requests for about a month now. At first everything went well; for the last week or so, when he sends a request to an Outlook recipient (I verified against an Exchange Webmail client, so Outlook itself is not the problem) the meeting request, when opened, shows the correct time; but when the recipient "accepts", the appointment shows up one hour early in the Outlook calendar.

    I made sure that both Macbook and Outlook user are on the same time zone; the time zone does not use DST; and I set iCal to "use time zone settings" or whatever that check-box says. Nothing I did makes any difference - meeting is one hour early.

    What's up with that?

  3. Chris Bedford says

    As far as I know, it doesn't make any difference what version of Windows the recipients are running -- XP or 7, or what mail server they are running, or what type of mailbox they have, POP3, IMAP, or Exchange.

    In my test case the recipient is on an Exchange 2010 client, and the error showed up using Outlook Web Access -- Outlook wasn't involved at all. I haven't yet gathered any data on others, but have asked the user (sender of meeting requests) to get that information from his recipients.

    Sender and all recipients are on South Africa Standard Time, which is GMT +2 with no daylight saving.

    I strongly doubt that the problem lies at the Outlook end, it looks to me like there is something not quite right in the iCal meeting request, but I'll continue keeping an open mind!

    • Diane Poremsky says

      Is everyone using the correct time zone - one without a DST option? In XP and older, it was possible to use a time zone with the right offset and not enable automatically update for dst. That will not work well in Win7.

      Assuming that is not the problem, I'd need to see the applicable ical code. Open it using notepad to view - I know one guy with problems had a weird TZ name in the ical and the best we could figure was Outlook had no idea what zone it was and did not adjust it for DST as a result (he was in a DST supported zone, so this may not apply to you).

  4. Chris Bedford says

    Addendum: I realise I am probably looking for solutions in the wrong forum (since it seems to be an iCal issue in this case), but of course I need to eliminate every possibility. Any help is appreciated :-)

  5. tasso papandreou says

    First of all, thanks for this facility!

    My devices are all at the right time but the problem persists. after looking into the time/date settings on my Android (Samsung galaxy s2), I realized that it takes time differently. For example, in Athens time zone, which is normally GMT + 2 hrs + DST, my android takes it as GMT + 3 hrs. There can't be much choice to avoid this since the android time is automatically adjusted by network. If I deselect the automatic adjustment and put GMT +2 hrs manually, I can't select a DST setting. I could deselect automatic DST from outlook, however I am afraid that I may run in different sorts of complications.

    Any advise would be appreciated. I need to sync at least my android phone with outlook.

    Many thanks.

    • Diane Poremsky says

      If your area honors DST, you need to use a time zone that uses DST. Not doing so can create a mess later, especially if you use windows 7 or 8.

      Outlook gets the time zone offset from the appt and should adjust the times accordingly but I've seen problems where the server uses a weird time zone label and outlook has no clue as to what it is. I'm not sure if this is behind your problem, as Outlook usually uses UTC and that would make the appt off by two hours, not one, if I'm thinking the times through correctly.

  6. Jezsea says

    When I send a meeting invitation from my Office Outlook 2013 calendar to my online Outlook calendar the online calendar shows the meeting one hour earlier. When I send an invitation from my online Outlook calendar to my Office Outlook calendar the meeting times are the same. I have checked the time zones on my computer and online and the only difference I can see is that my computer shows UTC+8 whereas my online calendar shows GMT+8. Can anyone help with this issue?

    • Diane Poremsky says

      Has it always been like this or is it a new problem? It sounds like there might be an issue with time zones and if its a new problem it could be temporary. Europe changed last week - GMT shouldn't be affected by it though.

  7. Jezsea says

    It is a new problem. I suspect it is with Microsoft. A couple of years ago we had DST but don't anymore so I am wondering if this change hasn't been picked up on the Microsoft online Outlook system somewhere. I saw yesterday the Outlook Calendar system was under maintenance so perhaps this will solve the issue.

    • Diane Poremsky says

      If the problem showed up about the time the time used to change in your area, then its a Microsoft problem for sure. I'm thinking something is using the wring time zone data and its possible the updates they are doing will fix it.

  8. stevied54 says

    I have had the same problem, calendar kept going back 1hr for any events etc I made or edited. I think I solved it (so far so good) time zone was set as london utc have now set time zone to (utc) Co-Ordinated Unversal Time. Appoitments etc made and edit have kept correct time made for. Phone Lumia 520 windows 8.

  9. Howie says

    Running Outlook 2010 and recently moved to a different time zone. I changed my PC's time zone settings and Outlook, predictably, shifted all of my appointments one hour (Eastern to Central). While I joined the masses in not wanting this behavior to occur, I used the Time Zone Data Update Tool and it appears to have successfully adjusted my future appointments back to their correct time slots.

    I noticed, however, past appointments remain one hour "off". Is this the expected behavior when using this Tool? If so, and one wants past appointments to be similarly handled (that is, to be accurate), is one relegated to manually modifying each and every one?


    • Diane Poremsky says

      I thought the tool applied to all appointments, past and future. You can either manually edit the past appointments or export them to Excel or CSV format then import. I usually move the ones I want to change to ta new calendar folder (use a list view to make it easier) then export this folder and import to the original folder.

  10. Howie says

    I thought the same, but when I ran it...future appointments only.

    Thanks for the tips regarding possibilities around modifying those seemingly untouched by the Tool.

  11. Jezsea says

    I notice that my Outlook time zone is UTC+8 whereas the Live calendar time zone is GMT+8. Not sure how I go about changing one or the other so they are the same.

    • Diane Poremsky says

      Unfortunately, you can't change it. I'm not even sure that is the problem. What operating system do you use? Are all time zone updates installed?

  12. Jezsea says

    I am using Windows 7(64). The latest time zone updates are installed. When the meeting invite arrives in my Live Inbox it shows the correct time. As soon as I accept the meeting it saves it into my Live Calendar one hour earlier. Maybe I can set my Live time zone to Irkutsk!

    • Diane Poremsky says

      i wouldn't message with changing times (at least not yet), it can mess things up more. I'm waiting to hear back from support about this.

  13. David Stone says

    Thank you so much for that suggestion. I was so frustrated at the timings being one hour wrong.

  14. Jeremy says

    I found that changing my Live Mail account settings Basic Info time zone to "Universal Time - GMT" rather than a specific time zone fixed the issue for me.

  15. Judith says

    In Outlook 2010, W7(64): When ET went forward for DST all the appt invitations that I sent out were an hour ahead even after I unchecked the automatic DST update. I spent hours trying to fix this (not to mention calling people to apologize and correct the meeting time).

    Solution: I set my computer clock an hour back, checked the automatic DST update. The clock jumped to the correct time and appt invitations sent out are now correct. A simple fix! Hope this helps others.

    • Diane PoremskyDiane Poremsky says

      If your computer clock (and the recipients) is on the correct time zone (with auto DST enabled) and is set for the correct time, the appointments should be correct. You'll have problems if you use the wrong time zone or don't use auto DST if your area uses DST.

  16. LG says

    Hi! I am using Samsung Note 4 and I am based in the Philippines. since the DST was lifted last March 8th, all my meeting invites coming from US colleagues were either off by a day or a day+1 hour. For example, a meeting set on Tuesday at 5pm, PST would show as Tuesday at 9am (PH time) instead of Wednesday, 8am since Philippines is ahead by 15 hours. Tried setting up my calendar using iphone 5 and everything is showing up just fine. Is it something to do with google calendar?

    More power!

    • Diane PoremskyDiane Poremsky says

      It could be google - or it could be something else. Make sure your computer and your google account is set to the correct time zone, has auto dst update enabled, if your zone supports it, and your computer time is correct. If the sender's aren't using the right time zone settings it can mess the calendar up too - Outlook uses UTC 0 for all appointments and adjusts it the appointment time to the local computer's time zone.

  17. Richard says

    Hi Diane

    If I send an invite for an all-day event from my work Outlook calendar (company-hosted Exchange) to my home email address, that works fine.

    But if I send an invite for an all-day event from my home Outlook calendar to my company email address, when it arrives in my work outlook calendar, it is -1 hours off in my work calendar - 23:00 - 23:00.

    Both home and work laptops are set to London/Dublin timezone in both Outlook>options and in Control Panel>date & time. Both are running W7 and Outlook 2010.

    Any ideas?


    • Richard says

      PS meant to add that it is of course presently BST here in the UK (i.e. daylight saving time, GMT +1) and that would appear to be being lost in one direction.

    • Diane PoremskyDiane Poremsky says

      It sounds like the TZ is getting lost on the appt so the server uses GMT. I've seen it between Outlook and some ical servers but it shouldn't happen with Outlook to Outlook/Exchange. (I don't have a solution off hand. )

    • Diane PoremskyDiane Poremsky says

      Is Outlook generating the appointment? I've seen issues where the appointment was generated outside of Outlook but defaulted to using UTC/GMT for the appointment because Outlook didn't know what time zone it was supposed to be in because appointment used a different naming convention for the time zones.

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