CREATE TABLE table_name_19 (date VARCHAR(255), city___state VARCHAR(255), team VARCHAR(255))
What is Date, when City / State is "Mallala , South Australia", and when Team is "R.J.MacArthur Onslow"?
    
SQL: SELECT date FROM table_name_19 WHERE city___state = "mallala , south australia" AND team = "r.j.macarthur onslow"