What was date of the game when the record was 31-15?
CREATE TABLE table_79898 (
    "Date" text,
    "Opponent" text,
    "Score" text,
    "Loss" text,
    "Record" text
)
SELECT "Date" FROM table_79898 WHERE "Record" = '31-15'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: What was date of the game when the record was 31-15? ### Input: CREATE TABLE table_79898 (
    "Date" text,
    "Opponent" text,
    "Score" text,
    "Loss" text,
    "Record" text
) ### Response: SELECT "Date" FROM table_79898 WHERE "Record" = '31-15'