SELECT "Date" FROM table_10138 WHERE "Venue" = 'corio oval'
Which date was corio oval the venue?
CREATE TABLE table_10138 (
    "Home team" text,
    "Home team score" text,
    "Away team" text,
    "Away team score" text,
    "Venue" text,
    "Crowd" real,
    "Date" text
)