MacBook Pro 13", macOS 10.15
It may have to do with the time zone offset. One or the other systems doesn't apply the offset correctly.
If they are all day events in Outlook, perhaps they are being sync'd as timed events with the wrong offset.
I don't know what Outlook uses as a time format. The region settings will only matter with respect to which time zone the Mac tries to convert the passed offset into, not what is being sent.
Do you have Time Zone support turned on in Calendar? Calendar will try to use the time zone information to correct for time zone changes. You pick the desired Time Zone to view in the top, right corner of the calendar viewer. Using the opposite setting of what you have selected to see if it helps.
Hi, I'm from Chile South America, and I have the same problem. And is not an issue from outlook.com, because the problem occur only in macOS Catalina, on iOS 13.3.1 no Sync issues.
Actually, now I don't sync O365 calendar to MacOS calendar to decrease scope to fix this problem. My MacOS contacts still have the adding 1 day e.g. I add the birthday 1 Jan 2020 in O365 portal, when I look in MacOS Contacts - it will show 2 Jan 2020 in bitrtday. Though, I try to fix all Time Zone in system and application. Moreover, MacOS Contacts doesn't have any Time Zone support.
Note : For other applications - Finder, Mail, Messenger, ..., they show the correct Date and Time.
The link I tried to post was a similar issue with Outlook but with Google calendar. Unfortunately, others reported that syncing between the two are not supported.
I wonder if Outlook uses a different time format that is confusing other systems.
If you can't tell what Outlook is sending in its "sync," I don't think I can provide any more help.
Perhaps this is related:
I don't think this is the issue. I have been using this combination (Microsoft Exchange cloud service + OsX + iOS) for more than 8 years with no issues.
Since Catalina this issue has appeared.
Thank you for your information - Barney. Actually, I checked the region setting in MacOS and O365 (online) that it is correct - my country/my timezone. Where can I check another offset?
When I add new one with birthday in O365 (online) or my iPhone11 contacts, Contacts in MacOS will be add 1 day.
I think there is a bigger problem.
I have been using Office365 for mail, calendar, and contact information for the past 8 years. On many of the contact entries, I also use Birthday information.
Since my update to Catalina, a very strange thing occured:
- On the OSX Catalina Contacts.app, Birthdays appear "correctly", as I have entered them - for instance Billy has birthday on January 2nd.
- On Outlook Web Access, Billy's birthdays appears as January 1st. So all contact birthdays have changed to one day earlier.
I cannot offer any explanation on this issue/problem. I suspect that Catalina corrupted data and that propagated to the Office365 server.
I tried changing on Outlook Web Access Billy's birthday date, from January 1st in my example, to January 2nd.
On Outlook Web Access now it reports properly, but on the OSX Catalina Contacts.app, they appear one day "later" than Office365, so the birthday date appears now as January 3rd!
Catalina add 1 day to contacts birthday and anniversary when syncing from/to Outlook.com
