Bodhi Day (sometimes Rohatsu or simply Bodhi) is a Buddhist holiday celebrating the day in 596 B.C. when Buddha attained enlightenment. In general, it is the northern part of Asia that celebrates Bodhi Day, while the southern region celebrates the enlightenment on Visakha. The traditional celebration day for this holiday is on the 8th day after the new moon before the new year, however with the popularity of the Gregorian calendar throughout the world, the new moon is not tracked by many people, and it is now commonly celebrated on December 8.
A few thousand years ago, prince Siddartha Gautama left his home, his family, and all his earthly possessions at the age of 29 to search for The Meaning of Life and its hardships. After six years of discipline and asceticism under the eye of numerous spiritual teachers, he still had not found his answer. Because of this, he sat under a Bodhi tree, (in some texts, a Pipal tree, Peepul tree, Pippul tree, or Bo tree) and vowed never to get up until he achieve understanding. He sat and fasted for a week, and on the morning of the eighth day came to several realizations which were to become the principles of modern Buddhism - The Four Noble Truths and later The Noble Eightfold Path.
Obviously, meditation is an important part of the celebration of this holiday, however, many Buddhists also celebrate with a traditional meal of tea, cake, and readings. These readings can be written by anyone in the sangha or from published sources. Others choose to express reverence and gratitude to the Buddhas, Bodhisattvas, and the Ancestors who are what we aspire to become. Through personal reflection, Buddhists are encouraged to learn from and emulated the profound example they have been given to follow to achieve enlightenment in their daily lives.