CREATE TABLE table_33611 ("Home team" TEXT, "Home team score" TEXT, "Away team" TEXT, "Away team score" TEXT, "Venue" TEXT, "Crowd" FLOAT, "Date" TEXT)

When did Essendon play as the home team?
SELECT "Date" FROM table_33611 WHERE "Home team" = 'essendon'
SELECT "Date" FROM "table_33611" WHERE "Home team" = 'essendon'