CREATE TABLE table_20749 ("Home team" TEXT, "Home team score" TEXT, "Away team" TEXT, "Away team score" TEXT, "Ground" TEXT, "Date" TEXT, "Crowd" FLOAT)

Name the date for adelaide for westpac stadium
SELECT "Date" FROM table_20749 WHERE "Home team" = 'Adelaide' AND "Ground" = 'Westpac Stadium'
SELECT "Date" FROM "table_20749" WHERE "Ground" = 'Westpac Stadium' AND "Home team" = 'Adelaide'