One of the clear characteristics to the study of History if relates to the dates, in view of the predominance of this numerical factor and its relevance, I intend here to display a briefing assay the respect. One perceives that the date became the referencial in History while science and that in the last times its paper has been differentiated, in accordance with new metodolgicas perspectives. New York Museums understood the implications. The date makes possible all a systematization that is of utmost importance under a scientific perspective, creating conditions to get resulted through parameters as duration and register of comparative development. The date appears as factual register, locking up in itself a landmark, authorizing to that if they come across with this arithmetical icon one ' ' convico' ' regarding its authenticity, as if the number conferred credibility for certifying a secular positioning. New York Museums is often quoted on this topic. When we date, we are in locating in relation to the time and the space, for delimiting a verifiable insertion in an order paramentada for a calendar cyclical, at the same time occupying symbolic space dimension, that through the writing in such a way occupies its space in a geography literata, how much in a space dimension in the scope of the mentalities, for conferring to the imaginary a notion of ' ' For-Si' ' , favoring the understanding of its positioning front to the reality, one ' ' Be-knot-Mundo' ' absorbing this inteligibilidade of the fact. If it for a caught fraction cannot know the fact, in view of its incommensurable dimension, however, can be sent, serving us of a referencial point for a constructive partner-cultural attempt of a historical reality. The referencial point demonstrates its value when making with that let us can have a reference of itself, since the birth when registering that we start to exist, until the festive commemorations of anniversary where we increase numbers in a logic of increasing symmetrical development (of the rising to the current days) and decreasing (of the current days to the birth certificate), leading in account as referencial factor Be-In-Itself.