CREATE TABLE table_51956 ("Home team" TEXT, "Home team score" TEXT, "Away team" TEXT, "Away team score" TEXT, "Venue" TEXT, "Crowd" FLOAT, "Date" TEXT)

Which date did South Melbourne play as the away team?
SELECT "Date" FROM table_51956 WHERE "Away team" = 'south melbourne'
SELECT "Date" FROM "table_51956" WHERE "Away team" = 'south melbourne'