Why are there usually two dates for the October revolution - November 6 and 7, 1917 or October 24 and 25, 1917.

On the 6th and the 7th of November 1917 (or 24 and 25 October on the Julian calendar, this is why the incident has often been referred to as the October Revolution).

Socialist revolutionaries headed by leader of the Bolshevik Party, Vladimir Lenin, launched an almost bloodless coup d'état against the provisional government of the Duma.