[Wiggo]

Thank you so much, chaley!

Unfortunately I get this error

calibre, version 7.19.0
FEHLER: Fehlgeschlagen: Unknown string format: S/R-Vorlagenfehler Formatter: Failed to scan program. Invalid input '#startdates, 0, 1, ','), 'dd MMM yyyy')' near the end of the program

Traceback (most recent call last):
  File "calibre\gui2\dialogs\metadata_bulk.py", line 198, in do_it
  File "calibre\gui2\dialogs\metadata_bulk.py", line 535, in do_all
  File "calibre\db\cache.py", line 85, in call_func_with_lock
  File "calibre\db\cache.py", line 1636, in set_field
  File "calibre\db\write.py", line 568, in set_books
  File "calibre\db\write.py", line 568, in <dictcomp>
  File "calibre\db\write.py", line 73, in adapt_datetime
  File "calibre\utils\date.py", line 114, in parse_date
  File "dateutil\parser\_parser.py", line 1368, in parse
  File "dateutil\parser\_parser.py", line 643, in parse
dateutil.parser._parser.ParserError: Unknown string format: S/R-Vorlagenfehler Formatter: Failed to scan program. Invalid input '#startdates, 0, 1, ','), 'dd MMM yyyy')' near the end of the program