It still works. You need to know your correction, but it's just like a computer with a slow clock. UTC doesn't explicitly state it, but it's reference is to a non inertial frame, on the earth's surface. (Rotational effects are far smaller than current clock errors, and transmission time errors)
Unfortunately even UTC isn't perfect once time dilation becomes a factor (eg. Satellites)
It still works. You need to know your correction, but it's just like a computer with a slow clock. UTC doesn't explicitly state it, but it's reference is to a non inertial frame, on the earth's surface. (Rotational effects are far smaller than current clock errors, and transmission time errors)