Japan

Constitution Day, May 3. Anniversary of the establishment of a parliamentary democracy in 1947.
Autumnal Equinox Day, September 22 or 23.
Black Ship Day, near July 15. Observed in Japanese ports to commemorate Commodore Perry's arrival in 1853. Celebrated in Yolosuka and Shimoda.
Children's Protection Day, April 17. Commemorates laws protecting juvenile delinquents.
Emperor's Birthday, December 23. A national holiday honoring the birthday of Emperor Akihito (b.1933).
Memorial Day, August 9. Observed in Nagasaki, Japan, August 9. Memorializes the victims of the second atomic bomb attack on this day in 1945. Also referred to as the Moment of Silence.
Hiroshima Peace Festival, August 6. A day for reflection on the anniversary of the dropping of the first atomic bomb on this date in 1945. Observance includes prayers for world peace in Buddhist, Shinto, and Christian services. Held at Peace Memorial Park. Also known as Hiroshima Day.
Labor Thanksgiving Day, November 23.
Martyr Day, February 5. Memorializes Saint Peter Baptist and others who were killed by Emperor Tagosama in 1597.
Memorial to Broken Dolls Day, June 3. A Buddhist observance when broken dolls are enshrined by a priest.
National Foundation Day, February 11. A national holiday that commemorates Japan's founding by the first emperor in 660 BC. This holiday was originally established as Empire Day in 1872, discontinued after World War II, then revived in its present form in 1966.
People's Holiday. [near may 4?].
Respect for the Aged Day, September 15.
Shigoto Hajime, January 2. According to superstition, this is a good day to begin work on something. Also known as Beginning of Work Day.
Health Sports Day, October 10. A public holiday commemorating the Tokyo Olympics in 1964.
Vernal Equinox Day, March 20 or 21.

Public holidays   New Year's Day, Adults Day, National Foundation Day, Vernal Equinox, Greenery Day, Constitution Day, Children's Day (May 5), Respect for the Aged Day, Autumn Equinox, Health Sports Day, Culture Day, Emperor's Birthday.

Cultural Festivals

Sanno Matsuri, June 15. A shinto festival honoring the mountain god Sanno.
Kakizome, January 2. [same as shigoto hajime?]
Greenery Day, April 29. [apparently this used to be the date of Emperor Day, perhaps that moved when they got a new emperor]
Jidai Matsuri, October 22. A festival in Kyoto celebrating Japan's history between the 8th and 19th centuries. Also known as Festival of Eras.
Culture Day, November 3. A day dedicated to promoting interest in freedom and culture. Prior to World War II, this day was a celebration of Emperor Meiji's birthday, who led the nation from feudalism.
Bon, occurs between July 13 and 15. A festival of Japanese Buddhists in memory of the dead. Observance involves lighting lanterns to guide the souls of the dead, who are believed to visit the Earth during this period. Observed also by Japanese communities worldwide. Also known as Feast of Lanterns.
Adults Day, January 15. Celebration for men and women reaching the age of 20. Also known as Seijin-No-Hi or Coming of Age Day.
Hina Matsuri, March 3. On this day girls display dolls, dressed in ceremonial costume, that have been handed down from mother to daughter for many generations. Also known as Doll Festival and Peach Festival. A similar celebration in Hawaii on this day is known as Japanese Girls' Day.
Gion Matsuri, February 16-24. A Shinto festival celebrated in Kyoto commemorating the end of a plague that ravaged the whole country. Celebrated with processions of decorated palanquins, which originally were used to invoke the protection of the gods to avoid further epidemics.
Bean-Throwing Festival, February 4. This is the last day of winter in the lunar calendar. People celebrate this day by throwing beans at each other. The custom derives from the legend of warriors who threw soy beans into the eyes of demons to chase them away. Also known as Setsubun.
Kambutsue, April 8. The Buddha's birthday. Observed by washing the image of the Buddha with amacha, a sweet tea. Also known as Hana Matsuri, or Flower Festival, because fresh flowers are brought to the temples. See also Buddhism.
Kite Battles of Hamamatsu, May 3-5. Celebration in Hamamatsu.
Tanabata, July 7. Also known as Star Festival because of the legend of two starts that meet only on the seventh night of the seventh month.
Tango-no-sekku, May 5. A national holiday corresponding to the Doll Festival for girls. Also known as Boys' Festival or Children's Day.
Hollyhock Festival, May 15. Celebration in Kyoto.
Shichigosan. The name means "seven-five-three". Children celebrate this when they turn three, then five, then seven.