When was the ENIAC invented?

A proposal for the machine was written in late 1942 and submitted to the Army for calculating Artillery Firing Tables. ENIAC was built between 1943 and 1945. Its first real program, simulation of Edward Teller's Classical Super fusion bomb, was run in December 1945 and January 1946, used a million punched cards. The simulation showed this fusion bomb design to be not workable. ENIAC was publicly announced and demonstrated in February 1946 (prior to this it was a Top Secret project).