The day Japan doesn't keep their own constitution.

2014, July 1 will be remembered as the darkest day in the history of Japan's constitutionalism because of the Abe Cabinet's approval to change the government interpretation of the supreme law to allow for the exercise of the right to collective self-defense. (cited from Asahi Shinbun, http://www.asahi.com/english/articles/AJ201407020044.html)