  We study longstanding problem of cosmological clock in the context of
Brans-Dicke theory of gravitation. We present the Hamiltonian formulation of
the theory for a class of spatially homogenous cosmological models. Then, we
show that formulation of the Brans-Dicke theory in the Einstein frame allows
how an identification of an appropriate cosmological time variable, as a
function of the scalar field in the theory, can be emerged in quantum
cosmology. The classical and quantum results are applied to the
Friedmann-Robertson-Walker cosmological models.
