Also known as 'Ocean Day' (umi no hi), it was only introduced into the calendar of public holidays in 1996 to celebrate the ocean and Japan's particular relationship with it. The date apparently marks the return of Emperor Meiji from a boat trip to Hokkaido in 1876. At the time, it was probably the nearest a Japanese emperor had ever come to leaving Japan, as Hokkaido was just being colonised.

Times
All day.