  We present an experimental optical implementation of a parallel-in-time
discrete model of quantum evolution, based on the entanglement between the
quantum system and a finite dimensional quantum clock. The setup is based on a
programmable spatial light modulator which entangles the polarization and
transverse spatial degrees of freedom of a single photon. It enables the
simulation of a qubit history state containing the whole evolution of the
system, capturing its main features in a simple and configurable scheme. We
experimentally determine the associated system-time entanglement, which is a
measure of distinguishable quantum evolution, and also the time average of
observables, which in the present realization can be obtained through one
single measurement.
