CREATE TABLE table_58888 ("Circuit" TEXT, "City / State" TEXT, "Date" TEXT, "Winner" TEXT, "Team" TEXT)

What is Date, when City / State is 'Mallala , South Australia', and when Team is 'R.J.MacArthur Onslow'?
SELECT "Date" FROM table_58888 WHERE "City / State" = 'mallala , south australia' AND "Team" = 'r.j.macarthur onslow'
SELECT "Date" FROM "table_58888" WHERE "City / State" = 'mallala , south australia' AND "Team" = 'r.j.macarthur onslow'