No, this is not normal. Clock should be vissible during day and night.
I suppose you have electronic (digital) dashboard ???
In that case a light bulb is located at the back of the clock, and probably broken.
In this case you have to build the electronic dash out of the dashboard (losen the screws), take the dash out and replace the lightbulb.
Clock should be vissible again.
Regards, Fleppenstijn