The clock on the wall decides whatever it wants to be

It can spin the fastest speed it can

It can turn midnight into afternoon in two seconds

Or count a minute in five days

It can move backwards and shift time

It can shift into an hourglass or a sundial

It can change into a different color, depending on your feelings

Or it can tell the weather, something clocks don't do

It can spin it's head, but not the arms

It can use the short arm as the long or the long arm as the short

It can completely freeze only when you are looking

Or it can make the most disturbing noise in the world

But what it can't do is tell the time