CREATE TABLE table_52959 ("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 essendon?
SELECT "Date" FROM table_52959 WHERE "Away team" = 'essendon'
SELECT "Date" FROM "table_52959" WHERE "Away team" = 'essendon'