The eight day mechanical movement, which is produced in the Black Forest of Germany, is wound once per week by raising the two pine cone weights. One weight powers the time and the other weight powers the cuckoo and cuckoo call.
All "8-day" Cuckoo Clocks are fitted with a mechanical movement that only requires winding every 8 days.
At the full hour, a small door opens and reveals a small cuckoo bird, which calls the number of hours (for example at 5 o'clock you will hear 5 cuckoo calls). The cuckoo bird also calls once on the half-hour.
The visible difference between 1-Day to 8-Day clocks are mostly the size of the weights with the 8-Day clocks having a noticeably larger and heavier weight than the 1-day clocks.