An analog clock, wow, how simple! Not really. You have to set the proper pivots for the rotation of the hands (I call them "arms", in German they would be called "Pointers"), and, mainly, you have to make the three hands rotate precisely. How? This is a typical scenario for EXPRESSiONS. Simple, but highly effective.
The key thought is that we can rotate the hand of a clock by setting the rotation value to "=time". This, however would take 360 seconds in order to finish one round. We need to accelerate the rotation by factor 6. From there it's easy: The other hands/arms of the clock depend on the rotation of the seconds.
Note: There's not a single KEYFRAME in this animation!