[itsme]

With dates in yyyy-mm-dd format as specified in ISO 8601 sorting of setlists works fine
https://en.wikipedia.org/wiki/ISO_8601

For sorting songs specifying "Sort Title" entries for your songs could achieve whatever you want. "Sort Title" overwrites existing alfabetical sorting rules for titles in lists. You might need to make it visible on the "Fields" tab of the song editor by activating it in the three dots menu under "Configure Fields". "Sort Title" is not shown in lists unless you configure it via Settings - Library Settings - Song Title Formatting"
The song from the screenshot is sorted in lists under A whereas it is displayed as "(Der) Aberglaub'n"