Back to the O&A Reference Ranch! "Cattle Bell Day" comes courtesy of Jim Norton... though he may actually refer to it as "Kettle Bell Day".
TRANSCRIPTION COURTESY OF JOSEPH HOUK - CASSIE'S BUCKET LIST "#22) Make up a holiday in the past and hope it catches on." [1853, We're back in ol' Nagel Gorge for the Cattle Bell Festival!] (CW, clanging her cowbell) "It's CATTLE BELL DAYYYY!!!" [PW isn't all that enthusiastic, but the jug band guys behind her look thrilled]