CREATE TABLE table_57255 ("Home team" TEXT, "Home team score" TEXT, "Away team" TEXT, "Away team score" TEXT, "Venue" TEXT, "Crowd" FLOAT, "Date" TEXT)

what is the date when the away team is melbourne?
SELECT "Date" FROM table_57255 WHERE "Away team" = 'melbourne'
SELECT "Date" FROM "table_57255" WHERE "Away team" = 'melbourne'