Fix for Exchange/iOS Outlook app 'birthday' bug

[German]Finally, Microsoft tries to fix an annoying bug in the iOS Outlook app, which in connection with Exchange servers displayed birthdays one day too early. The bug has been there for nearly than a decade.


The Outlook birthday bug under iOS

Users using an iPhone or iPad with iOS can install the Microsoft Outlook app there. The app also supports the synchronization of calendar data with Exchange servers. Actually a fine thing, in my opinion.

But administrators have probably had some grey hair, because the birthdays have been postponed by one day. Most of the time the birthday appeared one day too early. In 2018 I had the post Outlook app shows birthdays one day too early on this topic. In the blog post you can find the following screenshot with some information. Apparently there is a synchronization problem with Outlook on the iPhone.


The birthdays are displayed too early. The usual settings like time zone or Apple's iCloud preferences had already been checked. During the web search for the terms "Exchange Sync birthdays off by one day" I got exactly one hit in the Lenovo forum. In 2011, users there discussed the problem with Exchange. The solution was to open, change and save contact entries in Outlook.

This old Microsoft Answers forum thread from 2011 indicates that it is a known bug based on an old date field in the Hotmail database. The solution is an update of the contact in question. The same can be found in this entry in the Apple support forum from 2016. Here are several fixes proposed, from resetting the iOS device to adjusting the timezone settings. But changing the contact information and saving it has helped here as well.


Outlook User Voice will tell you even more. Since 2015, it has received over 260 votes. The problem probably only affects users who use Exchange ActiveSync outside the US time zone settings.

Fix foür Exchange Server 2016/2019

Maybe Exchange administrators have already noticed this – I became aware from German heise article. Microsoft published in mid-March KB article 4547706, addressing the 'birthday bug'. It says:

In Microsoft Exchange Server 2019 or Exchange Server 2016, you create a contact with a birthday by using the Outlook for Windows client. The time zone of the Outlook client is CET. When the contact is synced to an iOS native mail app, the contact shows birthday one day before the day entered in Outlook. iOS has a birthday calendar where a recurring appointment is created with the wrong date.

In the KB article, Microsoft then suggests a very simple fix for Exchange Server 2016/2019:

So you only need to install one of the mentioned cumulative updates for the Exchange Server. There is no fix for older versions of the Exchange Server. And the fix only works for future birthdays. Microsoft writes about this:

It's technically not possible to do changes for already created birthdays after you apply this update.

However, according to Microsoft, there are two workarounds available for the birthdays that are still incorrect:

  • Update the contact information. This will indicate the correct birthday along with this update.
  • Users can clean up the birthday calendar and add the birthdays again.

But these are workarounds that people have used before to fix the problem. Final question: Was anyone affected and do the cumulative updates mentioned above help?

Similar article:
Outlook app shows birthdays one day too early
Folder move bug with Microsoft Outlook 2016 mailboxes
Office 365: Outlook search in Exchange inbox broken
iOS 13.4.1 fixes VPN bug and Facetime issues
Exchange Server: 80% not patched against CVE-2020-0688
Vulnerability in Exchange Server 2010-2019.
Exchange Server 2013 Mail issues after Feb. 2020 Update
Microsoft recommends disabling SMBv1 on Exchange
Security information for Linux and Exchange
Attack to unpatched Exchange Servers (CVE-2020-0688)
Exchange Server 2013: Issue with Security Update KB4536988

Cookies helps to fund this blog: Cookie settings

This entry was posted in ios, Office, Software and tagged , , , . Bookmark the permalink.

Leave a Reply

Your email address will not be published. Required fields are marked *