Provide function to easily access the year, month and day part of a date:
Especially extracting the year is quite common in scripts, currently most examples use $left(%date%, 4).
We could even complement this with a full $dateformat(%date%, format) function. The format would work similar to https://picard-docs.musicbrainz.org/en/functions/func_datetime.html
$year(), $month() and $day() would then be just convenience functions on top of $dateformat()