This paper deals with verification of reachability properties on Time Petri Nets (TPN). TPNs allow the specification of real-time systems involving timing constraints explicitly. The main challenge of the analysis of such systems is to construct a finite abstraction of the corresponding (infinite) state graph preserving timed properties. Thus, we propose a new finite graph, called Timed Aggregate Graph (TAG), abstracting the behaviour of bounded TPNs with strong time semantics. The main feature the TAG compared to existing approaches is the encoding of the time information within the nodes of this graph. This allows to compute the minimum and maximum elapsed time in every path of the graph. The TAG preserves runs and reachable states of the corresponding TPN which allows for the verification of both event- and state-based properties