Nyepi is celebrated at the same time everywhere in Bali. It is not governed by the Balinese calendar, but by the Hindu Saka calendar and thus occurs every year between March and April.
In fact, these offerings to the Kala and Bhuta are only tempting to them. The priest carries out a big ceremony at the place. At his signal, to close the ceremony, everyone stands up and begins walking around the rug, making lots of noise, and hitting the ground with split bamboo sticks.
The fights and noise are designed to terrify all the demons that we lured there, and to chase them away by showing them that there are those much stronger than them on the island !