On July 9, 2015, Sonic is reportedly offering half priced cones all day long at all locations.
Note: This deal has been advertised with signage at various Sonic locations across the country. However, I cannot find any official mention of it online from Sonic. (If you find one, let me know!) So I’d recommend calling your store ahead of time to verify that they are participating.
Thanks, Freebies 4 Mom!