Particle represents an event that corresponds to a change of the system state. The DE schedulers process events in chronological order. Since the time interval between events is generally not fixed, each particle has an associated time-stamp. Time stamps are generated by the block producing the particle, using the time stamps of the input particles and the latency of the block.We assume in this chapter that the reader is thoroughly familiar with the DE model of computation. Refer to the User's Manual. Moreover, we assume the reader is familiar with chapter 2, "Writing Stars for Simulation". In this chapter, we give the additional information required to write stars for the DE domain.