If someone invited us to participate in a certain event, and if it didn't coincide with our schedule, we would most likely reply to our friend that 'I don't have time'. We are all too aware that sometimes time conditions us, and it makes our existence a central element in our being, including human action. It is for this reason that in this essay, captivated by the German philosopher Martin Heidegger, we approach time as the cornerstone of human existence, with the aim of showing and justifying the ontological revolution of the philosophical thought of the author under study throughout the history of philosophical thought, with the magnum opus Being and Time as a backdrop. Now, Heidegger, in his attempt to shake off the dust of philosophical thought, plunges to the core of being. He raises an old problem lying dormant in metaphysics or philosophy in general: Being and Time, Time and Being.