Tried this out yesterday and thought it was the bomb! Great job.
But I tried it out today and found that it returned nothing but the categories. Checking the grammar I found that the DATE specification failes on dates like "1 April" as it is only a 1-digit day, rather than as expected in the grammar as "01 April".
If the DATE is changed to "DATE: /0-9+ A-Za-z+ 0-9{4}/" then it works again.