where ε is the energy density of cosmological fluids, p is the pressure of cosmological fluids and n = N/V is the particle number density. The second term in the equation is the entropy variation due to irreversibility (the entropy production) . Despite to this result in the entropy production rate of the Universe, related to gravitation, we stress that the entropy production rate in our definition of time, as evaluated in relation , is generated by the interaction between the electromagnetic wave in the environment and the matter. Considering that the cosmic microwave background radiation represents this electromagnetic wave, this means that time doesn't present any local dependence. Consequently, time would change with the evolution of the universe, due to the variation of the cosmic microwave background radiation since the Universe formation up now.