Abstract: IEEE Std 610.12−1990 defines architecture as “the fundamental organization of a system embodied in its components, their relationships to each other, and to the environment, and the principles guiding its design and evolution.” [1] With previous versions of architecture frameworks, this was quite difficult. Modelling this evolution or the temporal aspects in architecture frameworks such NAF (NATO Architecture Framework), MODAF (Ministry of Defence Architecture Framework) or the Department of Defence Architecture Framework (DoDAF), have improved the state of the art. These architecture frameworks are based on the use of a four-dimensional ontology such as IDEAS where the spatio-temporal extent of an element is a crucial concept. This is embodied in DoDAF 2 as well as the re-engineering effort of MODAF (MODEM: which provides an IDEAS foundation basis for MODAF). Time can now be dealt with to a much greater extent than previously. The challenge is to identify areas of architecture where time can be modelled and how to take best advantage of it. The Unified Profile for DoDAF and MODAF (UPDM) delivers an implementation of DoDAF 2.0 and MODAF that provides a clear and concise way of expressing concepts dealing with time without requiring the user to become an expert in the DoDAF 2.0 or MODEM “internal wiring” and detailed ontological concepts. Since MODEM was not available when UPDM 2.0 was finalised, MODEM is a requirement for UPDM 3.0. MODEM has also been accepted as the basis for an upgrade of NAF and will make its appearance as NAF version 4.0. This paper will examine the temporal concepts defined in NAF (MODEM) and DoDAF 2.0 and show how time can be effectively integrated into a model to express essential temporal concepts.