Seeing the number of holes in that ceiling I really am concerned that the floor the clock is on is the same as the one with the holes, and I would advise that you secure the floor if you return to the attic.
The ceiling is fixed to the underside of the joists, the attic floor is fixed to the top side.
There's a non-zero chance the "floor" is just plywood laid across some of the beams and the holes are from people missing the beam in areas there's no plywood