Vesak, Vaisakha or Visakha Bucha / wān wísǎkhà būchā

Called by many names, such as Visakha Bucha, Visakhah Puja, Vesak, and Buddha Jayanti, this religious holiday is celebrated among devout Buddhists all over the world to honor Buddha, the great teacher

A Buddhist woman joins thousands of people in the "wien thien" ceremony marking Visakha Bucha Day at Buddhamonthon on 22 May 2005. – Natthiti Ampriwan

This Thursday is Visakha Bucha Day or the Buddha Day, another very important holy day for Buddhists. In 1999, the UN established Visakhah Puja Day or Vesak Day as an internationally celebrated day.

Many countries in Asia, such as Nepal, India, Sri Lanka, Malaysia, Indonesia, Singapore and Thailand celebrate this sacred day.

Visakha Bucha Day honors three significant events of Buddha's life - his birth, his enlightenment and his passing away. All three occurred on full-moon day of the sixth lunar month of the Thai calendar - around May. Buddhism originated in India and it was integrated into many other cultures as it spread throughout the region; and as a result, Visakha Bucha Day is celebrated on different in many different ways and on different days, as determined by a variety of calendars .

As on any Buddhist holy day, we Thais make merit in the morning by preparing and offering food to monks, going to a nearby temple to listen to or practice Dhama, and purifying our minds. In the evening, we go wien thien - a candlelit triple circumambulation of a nearby temple. To suit our modern lifestyle, many people practice the candle rite during the day.

Source : http://www.bangkokpost.net/education/site2007/pumy2907.htm