In this paper we consider dynamical equations x(Delta) = f (t, x) on time s
cales T. Here T is an arbitrary closed subset of R, x(Delta) denotes the di
fferential-difference. operator according to T. In the context of the quest
ion, whether the dynamical system phi : T x T x X --> X, generated by the a
bove equation, is a restriction of an ordinary continuous dynamical system
Phi : R x R x X --> X, generated by an ordinary differential equation, we s
tudy appropriate conditions and counterexamples. Our main tools are general
topological principles, Hermite interpolation and a certain version of cha
in rule for time scales.