CREATE TABLE table_29109 ("Series #" FLOAT, "Season #" FLOAT, "Title" TEXT, "Director" TEXT, "Writer" TEXT, "Original Airdate" TEXT)

What are the original air date(s) for season episode 20?
SELECT "Original Airdate" FROM table_29109 WHERE "Season #" = '20'
SELECT "Original Airdate" FROM "table_29109" WHERE "Season #" = '20'