In Phuket
The vegetarian festival was brought to Phuket and Trang, in the south of Thailand, by Chinese boatmen in the 19th century.
These Chinese had strong beliefs in Taoism.
Taoists worship nine Gods. These Gods are believed to take the form of planets and have direct influence on the 5 elements (earth, water, wind, fire and gold), that make up the physical body.
In the beginning, only the Chinese-Thai partook in the vegetarian festivals, but over time it's grown into a nationwide practice.
There are many devoted Chinese-Thai who eat jay food all year round. These Buddhists practice at the temple regularly.