CREATE TABLE table_51312 ("Home team" TEXT, "Home team score" TEXT, "Away team" TEXT, "Away team score" TEXT, "Venue" TEXT, "Crowd" FLOAT, "Date" TEXT)

What date was fitzroy the away team?
SELECT "Date" FROM table_51312 WHERE "Away team" = 'fitzroy'
SELECT "Date" FROM "table_51312" WHERE "Away team" = 'fitzroy'