I have created an application for Microsoft Teams with Bot Framework. It's showing to user some Adaptive card with Input.Date and Action.Submit button on it. The problem is, when Teams client app localization is set to different language than english (tested on US and GB - all worked fine) the data on backend service from Input.Date is not present in Action object's Value property. I was using web version of Teams client for testing. I have tried it with polish and german languages.
And on english localization it works fine:
I have tested it also on desktop version of Teams and result was a little bit different - one of the dates did came through, but with day replaced with month (difference in polish and english date format), the other one has selected 28th november, so number 28 couldn't be converted to month number.
It seems that problem is with the Teams client application itself and it's date input handling. I have found some issue ticket on similiar problem on MS Github: Github issue ticket. Ticket is from april and since then not much have changed.
My question is: Is there some workaround for this problem that allowes using localization other than english and still get valid data from Input.Date or is there work beeing done on this topic?
The bug is described in detail here: https://github.com/OfficeDev/BotBuilder-MicrosoftTeams/issues/195
Long story short, Teams submit actions try to interpret each date value from the string representation as though it's in American English, regardless of the locale settings.
Like Gousia said, the problem is being worked on.