When did a Competition of friendly, and a Score of 2 1, and a Venue of philadelphia , pennsylvania occur?
CREATE TABLE table_name_4 (
    date VARCHAR,
    venue VARCHAR,
    competition VARCHAR,
    score VARCHAR
)
SELECT date FROM table_name_4 WHERE competition = "friendly" AND score = "2–1" AND venue = "philadelphia , pennsylvania"
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: When did a Competition of friendly, and a Score of 2 1, and a Venue of philadelphia , pennsylvania occur? ### Input: CREATE TABLE table_name_4 (
    date VARCHAR,
    venue VARCHAR,
    competition VARCHAR,
    score VARCHAR
) ### Response: SELECT date FROM table_name_4 WHERE competition = "friendly" AND score = "2–1" AND venue = "philadelphia , pennsylvania"