The word "charge" is often used as a synonym for both the generator of a symmetry, and the conserved quantum number (eigenvalue) of the generator. Thus, letting the upper-case letter Q refer to the generator, one has that the generator commutes with the Hamiltonian [ Q, H ] = 0. Commutation implies that the eigenvalues (lower-case) q are time-invariant: ⁠ dq / dt ⁠ = 0.