Date field always null when using SwagProductBasics plugin

Hey!

I’m trying to create a similar plugin to SwagProductBasics plugin. It is a basic CRUD plugin that takes a custom model and the CRUD operations are then available in the backend. I was following this tutorial and ran into the problem that i’m unable to update the date field(s). The problem is present in the original plugin as well. The value for the date parameter (in case of the original plugin: createDate) is always null when creating/editing the model from the backend gui. When I inspect the POST request, all other fields are populated as expected except the createDate.

Is this a bug, or is the tutorial/plugin missing some information that would implement this functionality? Does it have something to do with the format of the date? When i use the datepicker the date format is in dd.mm.yyyy

Thank you for any help.