Birthday calender entries in wrong date format (in sidebar)

[motey]

Steps to reproduce

1. Create a contact with birthday
2. Have a look at the dates in the webinterface calender app
3. Open the Sidebar of a date

Expected behaviour

See the date in my local format without any time as a birthday is a all day event

Actual behaviour

See the date in US format with 12:00 AM with local wording mixed in (German in my case)
"von 01/16/2020 um 12:00 AM"

Calendar app

Calendar app version:: 2.0.1

CalDAV-clients used: Webinterface

Client configuration

Browser: 72.0.2 (64-Bit)

Operating system: Windows 10

Anybody else?

[motey]

btw: My config in "Account"-"Personal Informations"-"locale" is set to "Deutschland"