CREATE TABLE table_16779 ("Race Name" TEXT, "Circuit" TEXT, "Date" TEXT, "Winning driver" TEXT, "Constructor" TEXT, "Report" TEXT)

Which date did the race name XII Pau Grand Prix take place on?
SELECT "Date" FROM table_16779 WHERE "Race Name" = 'XII Pau Grand Prix'
SELECT "Date" FROM "table_16779" WHERE "Race Name" = 'XII Pau Grand Prix'