MIAMI--(BUSINESS WIRE)--What started as the ‘McWhopper proposal’, a friendly peace offering from Burger King to McDonald’s to raise awareness for Peace Day, has developed into a much larger partnership. After several restaurants approached Burger King to unite in honor of Peace Day on September 21st, a momentous decision was made and the Peace Day Burger™ was born. A collaboration between Denny’s, Wayback Burgers, Krystal, Giraffas USA, and of course, Burger King, the Peace Day Burger will comb