Describe the bug
If i try to edit the metadata of any book, testet multiple, and save I get the error:

Error editing book: Object of type datetime is not JSON serializable

To Reproduce
Steps to reproduce the behavior:

1. Go to the page of any Book
2. Click on edit metadata
3. Scroll down to save
4. The error will be on the bottom of the page and data is not saved

Expected behavior
That the changed metadata is stred

Screenshots
Error:

Configuration(please complete the following information):

• OS: [Debian

V3.0.4 mit Docker

Additional context