In this paper, we propose a novel one-pass and tree-shaped tableau method for Timed Propositional Temporal Logic and for a bounded variant of its extension with past operators. Timed Propositional Temporal Logic (TPTL) is a real-time temporal logic, with an EXPSPACE-complete satisfiability problem, which has been successfully applied to the verification of real-time systems. In contrast to LTL, adding past operators to TPTL makes the satisfiability problem for the resulting logic (TPTL+P) non-elementary. In this paper, we devise a one-pass and tree-shaped tableau for both TPTL and bounded TPTL+P (TPTL b +P), a syntactic restriction introduced to encode timeline-based planning problems, which recovers the EXPSPACE-complete complexity. The tableau systems for TPTL and TPTL b +P are presented in a unified way, being very similar to each other, providing a common skeleton that is then specialised to each logic. In doing that, we characterise the semantics of TPTL b +P in terms of a purely syntactic fragment of TPTL+P, giving a translation that embeds the former into the latter. Soundness and completeness of the system are proved fully. In particular, we give a greatly simplified model-theoretic completeness proof, which sidesteps the complex combinatorial argument used by known proofs for the one-pass and tree-shaped tableau systems for LTL and LTL+P. reflected in the computational complexity of its satisfiability problem, which is EXPSPACE-complete. Originally proposed as a formal tool for the verification of real-time systems, it recently found interesting applications in the area of artificial intelligence, to encode a meaningful class of timeline-based planning problems [5]. This and other application scenarios benefit from/require the use of past operators, which allow the logic to compactly predicate about events in the past of the current time point. However, in contrast to the case of LTL, where past operators can be supported without harm, adding them to TPTL greatly increases the complexity of its satisfiability problem, which becomes non-elementary [1]. For this reason, bounded TPTL with Past (TPTL b +P) has been introduced [5], which supports past operators, but suitably restricts their use in order to recover an EXPSPACE-complete satisfiability problem. While initially introduced as a specific tool to encode planning problems, TPTL b +P is interesting by itself, since it enables the use of past operators in a fairly natural way.In this paper, we exploit the extensibility of the aforementioned tableau system to provide a one-pass and tree-shaped tableau method for TPTL and TPTL b +P. We present both tableau systems, which are very similar, in a unified way by first (i) factoring out the common structure, and then (ii) showing how to specialise it in the case of TPTL (future-only) and TPTL b +P (bounded) formulae, thus obtaining a one-pass and tree-shaped tableau system for both logics. To show how the tableau for TPTL b +P formulae works, (iii) we characterise the semantics of the logic in terms of a guar...