As an update, since we’ve still been seeing issues around date formatting, so we’re pursuing another fix that should help: If you’re using Planner within Teams, we will default to using the same language/local as Teams.
If you’re seeing this issue persist outside of Teams and your language/locale is set properly for your Office account, please let us know in the comments below!
The Planner Team
An error occurred while saving the commentRichard Griffin commented
Latest update from Microsoft - cut and paste so please don't blame me for the appalling spelling and grammar.
This is Sagar from the Office 365 Support.
Issue: Teams date format wrong
We have checked that this particular feature in Teams desktop client has not yet rolled out:
You can follow the link shown below:
In traditional American usage, dates are written in the month–day–year order.So its taking bydefault this format.But for webportal its not.
Thank you for being a part of Microsoft Family.
Thanks & Regards,
Microsoft O365 Support Team