On a full moon, 1,250 Arahants – or men worthy of veneration for their understanding – came together, with no prior arrangement, to visit the Buddha.
He ordained them and passed to them the basic principles of Buddhism: To eschew all evil, to do only what is good, and to cleanse the mind, along with other teachings.
Devout Buddhists traditionally make a special effort to go to the wat on this day to perform merit-making ceremonies.
For more secular people, the day is also a no-alcohol day.
Although technically voluntary, a ban on the sale or serving of alcohol until 6 am tomorrow is interpreted with different degrees of zeal by various authorities.