Yay! In honor of Tax Day, Sonic will be offering 1/2 priced- cheeseburgers all day long tomorrow, April 15th! No coupon is needed. Visit Sonic’s Facebook Pagefor details!Yay! In honor of Tax Day, Sonic will be offering 1/2 priced- cheeseburgers all day long tomorrow, April 15th! No coupon is needed. Visit Sonic’s Facebook Pagefor details!