Hello Markus

We cannot replicate this issue on local installations, development, staging, and demo websites. No one else reported this either, so there's no issue with the plugin.

Please provide me a temporary WP-admin (administrator) user for your site where this happens, so we could log in and take a look ‘from the inside’ as that’s the most efficient way to see and resolve the issue. 

We do not interfere with any data or anything else except for the plugin (in case that’s a production version of the site), and of course, we do not provide login data to third parties. 

You can write credentials here just check PRIVATE Reply so nobody can see them except us.

Thanks for the credentials, Markus, I received the email and resolved your problem.

The issue was with the date format you've added in WordPress' General settings. You can see in there that the date comes out wrong even in WP Settings:

"yy" doesn't exist as a valid PHP date format. "y" is a 2-digit year format, and you basically duplicated it, so for 2021 it would be "2121". If we were in 2022, it would be "2222", for 2023, it would be "2323" and so on. To use the whole year, it needs to be capital "Y", like this:

You can now see the correct format below, and also when you book an appointment in Amelia.

You're welcome, Markus

Glad I could be of service.

If you have any further questions or issues, please feel free to open a new ticket, and we'll gladly help.