A method is presented for deriving test suites with the guaranteed fault coverage for deterministic possibly partial Timed Finite State Machines (TFSMs). TFSMs have integer boundaries for time guards and the time reset operation at every transition; for TFSM implementations the upper bound on the number of states is known as well as the largest finite boundary and the smallest duration of time guards. We consider two fault models and present corresponding techniques for deriving complete test suites. In the first fault model inputs can be applied at integer time instances while in the second fault model time instances can be rational. The derivation method for integer time instances is extended to the case when the number of states of an implementation under test can be larger than the number of states of the given specification.