Why is "Marine Day" barely known outside Japan?
Well, probably because most Japanese don’t even have the slightest clue of what “Marine Day” represents other than it being another national holiday.The date is actually to commemorate the “Meiji Emperor and his 1876 voyage in the Meiji Maru an iron steamship constructed in Scotland in 1874. The voyage included a trip around the Tōhoku region, embarking on a lighthouse boat in Aomori, and a brief stop in Hakodate before returning to Yokohama on July 20 of that year.”So, basically the date the Meiji Emperor returned to Yokohama which I can guarantee even people living in Yokohama have absolutely no idea about. If Japanese don’t know anything about “Marine Day” it would make sense that people outside of Japan would have even heard of it.In the 1990’s and 2000’s the Japanese Government decided that Japan required more national holidays. The reasoning was nobody was taking time off from work and not using their accumulated holidays, so they needed a way to force workers and corporations to take time off from a health perspective. Since then there have been quite a few new national holidays.“Beginning in 2000, Japan implemented the Happy Monday System, which moved a number of national holidays to Monday in order to obtain a long weekend:Coming-of-Age Day: January 15 → 2nd Monday of January, starting in 2000.Marine Day: July 20 → 3rd Monday of July, starting in 2003.Respect for the Aged Day: September 15 → 3rd Monday of September, starting in 2003.Health and Sports Day: October 10 → 2nd Monday of October, starting in 2000.In 2006, the country decided to add Shōwa Day, a new national holiday, in place of Greenery Day on April 29, and to move Greenery Day to May 4. These changes took effect in 2007.In 2014, the House of Councillors decided to add Mountain Day to the Japanese calendar on August 11, after lobbying by the Japanese Alpine Club. It is intended to coincide with the Bon Festival vacation time, giving Japanese people an opportunity to appreciate Japan's mountains.”As you can see, Japanese national holidays change so often that calendar makers have been known to wait till the last minute before printing since 2005 when millions of calendars had to be scrapped due to changes for 2006 and subsequently 2007.