Commutator relations may look different than in the Schrödinger picture, because of the time dependence of operators. For example, consider the operators x (t 1), x (t 2), p (t 1) and p (t 2). The time evolution of those operators depends on the Hamiltonian of the system. Considering the one-dimensional harmonic oscillator, H = p 2 2 m + m ω ω 2 x 2 2 , the evolution of the position and momentum operators is given by: d d t x ( t ) = i ℏ ℏ [ H , x ( t ) ] = p m , d d t p ( t ) = i ℏ ℏ [ H , p ( t ) ] = − − m ω ω 2 x .