Passage of ‘Time’ in the Formation of Rule of Customary International Law: Revisiting Legal Doctrine and ICJ Jurisprudence

Comparative Study of the role of ‘Time’ in the formation of Customary International Law, shows the different, contradictory and even conflicting ideas. Being necessary the existence of the objective element, i.e. general practice, and the subjective one, i.e. accepted as law, so called opinio juris, for the  formation of such rules in international law, the present paper seeks the following question that what and how is the role of ‘Time’ factor in formation and subsequently identification of rule of customary international law? As international judicial decisions and teachings of the most highly qualified publicists of various nations have been considered as the subsidiary means to identifying legal rules, the present paper studied the jurisprudence of International Court of Justice and teachings of the most highly qualified publicists of this field, and studies of International Law Commission reporter as the most important entity in the codification and progressive development of international law and figured out there has been a conceptual evolution in the said conception. Explaining the classical and curren t ideas in question, distinguishes the outcasted concepts from the accepted one and finds that the time factor affects the two said elements in Customary International Law. The time factor is necessary in the formation of such rules, but the period of this time is and must be different by virtue of each case.