CREATE TABLE table_20420 ("Episode Number" FLOAT, "Air Date" TEXT, "Guest Host" TEXT, "Musical Guest  ( Song performed ) " TEXT, "Who knows the most about the guest host? panelists" TEXT)

On what date were Gary Lucy and Susie Verrico the panelists.
SELECT "Air Date" FROM table_20420 WHERE "Who knows the most about the guest host? panelists" = 'Gary Lucy and Susie Verrico'
SELECT "Air Date" FROM "table_20420" WHERE "Who knows the most about the guest host? panelists" = 'Gary Lucy and Susie Verrico'