Buddha's Birthday

Buddha's Birthday, the birthday of the Prince Siddhartha Gautama, is a holiday traditionally celebrated in Mahayana Buddhism.

In many east Asian countries Buddha's Birth is celebrated on the 8th day of the 4th month in the Chinese lunar calendar (in Japan since 1873 on April 8 of the Gregorian calendar), and the day is an official holiday in Hong Kong, Macau, and South Korea. The date falls from the end of April to the end of May in the Gregorian calendar.
The primarily solar Gregorian calendar date varies from year to year (2011: May 10, 2012: April 28 2013: May 17, 2014: May 6, 2015: May 25, 2016: May 14, 2017: May 3, 2018: May 22).
As a result of the Meiji Restoration, Japan adopted the Gregorian calendar in lieu of the Chinese lunar calendar in 1873. In many Japanese temples, Buddha's birth is celebrated according to the Gregorian calendar dates, and rarely on the orthodox Chinese calendar dates.

Buddha-Siddhartha Gautama
Gautama Buddha, also known as Siddhartha Gautama, Shakyamuni, or simply the Buddha, was a sage on whose teachings Buddhism was founded. Born in the Shakya republic in the Himalayan foothills, Gautama Buddha taught primarily in northeastern India.
Buddha means "awakened one" or "the enlightened one." "Buddha" is also used as a title for the first awakened being in an era. In most Buddhist traditions, Siddhartha Gautama is regarded as the Supreme Buddha (Pali sammasambuddha, Sanskrit samyaksa?buddha) of our age.
Gautama taught a Middle Way between sensual indulgence and the severe asceticism found in the Sramana (renunciation) movement common in his region. He later taught throughout regions of eastern India such as Magadha and Ko┼Ťala.
Gautama is the primary figure in Buddhism, and accounts of his life, discourses, and monastic rules are believed by Buddhists to have been summarized after his death and memorized by his followers. Various collections of teachings attributed to him were passed down by oral tradition, and first committed to writing about 400 years later.