The advent of distributed memory parallel muchines turns feasible the design and implementation of dedicated environments for distributed applications. This puper addresses such a realization by presentiny a distributed kernel, called FLORIA, whose uim is to provide a virtiial time environment for, application proyr'ums (distributed discrete eveiit simulation is the most krwwn of the applications based on such a virid time - the so called simulation time - and consequently constatutes the paradigm of this class). This paper presents first basic feutures of the virtual time concept and then describes the time-related aspects of the amplementataon of a distributed kernel dedicuted to virtual time driven applications.