SELECT "Date" FROM table_53709 WHERE "Venue" = 'vfl park'
On which date was the venue of vfl park used?
CREATE TABLE table_53709 (
    "Home team" text,
    "Home team score" text,
    "Away team" text,
    "Away team score" text,
    "Venue" text,
    "Crowd" real,
    "Date" text
)