Marine Day, also known as Umi no Hi, a Japanese holiday celebrated on July 17, 2023. The day is also known as Sea Day or Ocean Day. It is celebrated annually on the third Monday in July. Until 1996 the day was called Marine Memorial Day, which first was established in 1941 by Communications Minister Shozo Murata. The purpose was to commemorate the Meiji Emperor and his 1876 voyage on an iron steamship.
Since 1996 Marine Day is a public holiday, and it was the first one to take place during the summer months. Due to the Happy Monday System, the reform which creates long weekends using Monday holidays, Marine Day was moved from July 20 to the third Monday in July in 2003. Many people celebrate the holiday by taking a day trip to the beach or joining ocean-related festivities.