CREATE TABLE table_50917 ("Episode" TEXT, "Air Date" TEXT, "Timeslot" TEXT, "18-49" TEXT, "Viewers" FLOAT)

What was the air date of the episode that has an 18-49 of 2.2/7?
SELECT "Air Date" FROM table_50917 WHERE "18-49" = '2.2/7'
SELECT "Air Date" FROM "table_50917" WHERE "18-49" = '2.2/7'