No. It gets dimmer with time, as it is on all the time. Actually there is no difference between on and standby, it's just that the time digits fade more quickly.

It is definately dimmer when on standby - probably half as bright.

That's odd as mine is definitely the same (checking just the time digits).

Possibly it depends on the hardware version - mine is 1.0 - though I don't think anyone has commented on this in this forum.

When the unit is on standby you cannot see the time in normal daylight(not bright sunlight!) only when the room is overcast.

As said, since the clock digits are continuously lit these wear out sooner than the channel/function display which is only lit when the PVR is on.