Consider a one-dimensional lattice boson system with the Hamiltonian in a finite box Λ, H_Λ = K_Λ + U_Λ. Here K_Λ is the kinetic energy and U_Λ is the potential energy corresponding to a finite-range pair interaction. For a class of states T of the infinite system, we prove the existence of the limit T_t(A) = lim_(Λ→Z) T(e^(itH_Λ)*Ae^(-itH_Λ)) for any t ϵ R^4 and any local observable A. Thereby a family {T_t, t ϵ R^4} of locally normal states is determined which describes the time-evolution of the initial state T
