The ThirdReality app allows adjusting the Clock's numeric display like a dimmer light. You can set the brightness level and turn it on/off. This is not yet available in the Hubitat driver.
This capability was added in a recent firmware update to the device.
I'd like to be able to use its motion sensing ability to turn the clock on only when motion is sensed as I find the clock too bright at night even at the lowest brightness, but would like to see the time on it when I get up.