Friday Tractor of Hartford, Michigan, was founded by David Friday. Friday built his first tractor in the 1930s using Ford car and truck parts. Friday appears to have been involved with the Love Tractor design, also of Michigan, around World War II. Following the war Friday produced improved models of his own design. By the late 1950s Friday had stopped building tractors but continued to manufacture specialized agricultural equipment.
FridayTractor.com - collectors' site
Friday article - history of Friday at Gas Engine magazine