I’m afraid I don’t know what your timestep values represent, and I’m not that versed in Python date handling to offer suggestions.
I think you are saying ParaView is displaying a time value that isn’t in your dataset. It is displaying the time requested in ParaView, but the data displayed is the closest available timestep, so there is indeed a mismatch in that regard. I suppose you could round the ParaView time to the closest one in your time array with some Python function.