Table schema:
CREATE TABLE table_name_92 (podcast_date VARCHAR, run_time VARCHAR, episode_number VARCHAR, historical_references VARCHAR)

Question: What is the date of the episode that is before 307, run time equals 5:48 and has P.T. Barnum as the topic?
SQL: SELECT podcast_date FROM table_name_92 WHERE episode_number < 307 AND historical_references = "p.t. barnum" AND run_time = "5:48"