In order to save the world from a nuclear holocaust in 2045, Doc Brown must push the technological age back at least 50 years preventing Mattel Hoverboards and Mr. Fusion from being created.
1982
2004
2008
2003
2002
2000
2021
2017
1977
2016
2001
2019
1961
1990
2013
2014
1980
1999