In this paper we describe STP, a novel algorithm for temporal planning. Similar to several existing temporal planners, STP relies on a transformation from temporal planning to classical planning, and constructs a temporal plan by finding a sequence of classical actions that solve the problem while satisfying a given set of temporal constraints. Our main contribution is that STP can solve temporal planning problems that require simultaneous events, i.e. the temporal actions have to be scheduled in such a way that two or more of their effects take place concurrently. To do so, STP separates each event into three phases: one phase in which temporal actions are scheduled to end, one phase in which simultaneous effects take place, and one phase in which temporal actions are scheduled to start. Experimental results show that STP significantly outperforms state-of-the-art temporal planners in a domain requiring simultaneous events.