It didn't work. Almost everything went ok but I couldn't filter just the max_date. It cannot parse value 'max_date' with date pattern yyyy-MM-dd HH:mm:ss Z
What is amazing is that when I look to the meta data view the max_date attribute is type date_time. I've tried to change the type using Date to Nominal, Date to Numerical, Numerical to Date, Nominal to Date, Guess Types but all of them either don't list max_date at the attribute list or don't make Filter Example work.