An 8 day cuckoo clock will run a full week before the clock will need to be wound (See winding instructions for help on how to wind the clock).  A 1 day cuckoo clock will run a full 24 hours before the clock will need to be wound.  Another difference between the clocks is the size of the weights. An 8 day cuckoo clock has weights that are bigger in size and heavier in weight, whereas the 1 day cuckoo clock has smaller and lighter weights.