A good clock cannot show dilated time:

The clocks are required to tell time, and that clocks oscillate so such oscillations follow the wave equation.

In addition, the flow of time requires a 360 degree dial or scale so that the oscillating part of the clock can represent the correct time at a specific frequency, so that the oscillating state of a certain fixed frequency is maintained.

But if time dilates due to motion or gravitational effect then the dilated time within the dial of a 360 degree watch will not be able to accurately display the time dilated, so the watch cannot display the dilated time on its specific 360 degree dial. Can't be seen at all. So how can you measure time dilation on the clock? No one can do that.