The :today input is always as yyyymmdd regardless of your date format setting for the journal.
So to break it apart we need specific subs.
The original user posted they used a link to their journal as the property which has a format of yyyy/mm/dd thus would need different subs to extract.
If your journal refs are as previously stated, then the query from the original post will not work for you.
The query that Darwis linked to, would work regardless of your journal date format settings.