Mass tagging Mp3tag convert date to single date format string - click in the box below, press CTRL+A and then CTRL+C, then click Back to return to the instructions.

$regexp($regexp($regexp($regexp($regexp(%year%,'^(\d\d\d\d(-\d\d(-\d\d)?)?)$',~\1),'^(\d\d\d\d-\d\d)-\d\d--\d\d$',~\1),'^(\d\d\d\d)-\d\d-\d\d--\d\d-\d\d$',~\1),'^[^~]*$',),'~',)