How should we characterize the dynamics of the Web? Whereas network maps have contributed to a redefinition of distances and space in information networks, current studies still use a traditional time unit -the second- to understand the temporality of the Web. This unit leads to the observation of exogenous phenomena like day-night patterns. In order to capture the intrinsic dynamics of the network, we introduce an innovative -yet simple- concept of time which relies on the measure of changes in the network space. We demonstrate its practical interest on the evolution of the Github social network.