The clockwork mechanism provides a useful picture to understand extra dimensions via continuum limit of the scheme (continuum clockwork). The continuum clockwork can find its concrete realization in the general linear dilaton model (GLD). GLD can be defined by classical scale invariance in the presence of supersymmetry, which implies a non-trivial selection rule for radiative corrections to dilaton potential. Known examples of GLD are heterotic M-theory, type II little string theory and non-critical string theories. Previously unexplored Kaluza-Klein spectra and couplings can be captured in GLD, which will be shown to be actually present in heterotic M-theory.