This festival generally takes place in the month of May
The best time to come to Rayong is between November and March. Aside from maybe September, there is no time when it is really not advisable to come to Rayong.
We are one week away from Chinese New Year (January 25th, 2020) and despite a lot of mail and detailed information requests from various Tourist Offices in several cities, I unfortunately did not get all the details that I would have liked...