On June 25, it was declared as Samvidhaan Hatya Diwas. This date commemorates the period of emergency rule from June 25, 1975, to March 21, 1977, when then Prime Minister Indira Gandhi's government invoked special provisions of the Constitution to implement significant executive and legislative changes. Under which article of the Indian Constitution can the President declare a national emergency when the security of India or a part of it is threatened by war, external aggression, or armed rebellion?