In general, Thailand is an open and friendly country with nice people. There are several travel taboos in Thailand： 1. Do not show disrespect toward the Thai Royal Family and Buddhism. 2. Do not criticize the regime and the ruling family. 3. Try not to wear pure red clothes when travel in the election year of Thailand.
For holidays and festivals, the most important ones are:
New Year’s Day (Jan): Even if the traditional New Year is celebrated in April (Songkran Festival), the year changes on January 1st. Thai people start counting the years from Buddha's birth, 543 years before Jesus Christ, but they also use the western calendar. So year 2015 is more commonly referred to as year 2558. If you are in Bangkok, the countdown usually takes place at the World Trade Center.
Makha Bucha (Feb) : It commemorates the day when 1250 disciples gathered without prior notice and listened to Buddha elaborate some of his most important teachings in a sermon. Thai people usually go to the temple from early morning, participate in ceremonies, and at night they walk three times around the temple with candles.
Songran Festival (Apr): Thai's traditional New Year, and the most important holiday of the year. Water is sprayed on statues of Buddha as a means of purification. If you are in Thailand, prepare yourself to get wet too, as Thai people also splash water on each other!
Visakha Bucha (May): This day commemorates the birth, the enlightenment and the entry into the nirvana of Buddha. Temples throughout the country are crowded with people listening to sermons about Dharma (Buddha's teaching) and in the evening there is a candlelit procession around the main building of the temple containing the Buddha statues.
Queen’s Birthday (Aug) : The birthday of Queen Sirikit, who was born in 1932, is also celebrated as Mother's Day. As the Queen was born on a Friday, and light blue is the color associated to Friday, people usually dress in light blue, to show their love and respect.
Loy Krathong(Nov): Loy Krathong happens on the first full moon day of November. Thai people buy or make a krathong, which is like a small boat made of banana tree and banana leaves, with flowers and a candle in the middle. At night the krathongs are set adrift on a nearby river or pond, as an offering to the spirit of the water to wash away the sins. According to an ancient proverb, when a boy and a girl float a krathong together, they will be lovers either in this life or the next.
King’s Birthday (December): This is the birthday of Bhumibol Adulyadej the Great, "the beloved King and father of all Thai people", and it is also Father's Day (like the Queen's birthday is also Mother's Day). All Thailand is dressed in yellow on this special day, as the King was born on a Monday, the day of the week to which yellow is associated. Thai people often wears a yellow shirt on Mondays, throughout the year, or on every occasion where they want to show their love and respect of the King.