  Model checking timed automata becomes increasingly complex with the increase
in the number of clocks. Hence it is desirable that one constructs an automaton
with the minimum number of clocks possible. The problem of checking whether
there exists a timed automaton with a smaller number of clocks such that the
timed language accepted by the original automaton is preserved is known to be
undecidable. In this paper, we give a construction, which for any given timed
automaton produces a timed bisimilar automaton with the least number of clocks.
Further, we show that such an automaton with the minimum possible number of
clocks can be constructed in time that is doubly exponential in the number of
clocks of the original automaton.
