This day falls on August 11th each year unless on a weekend the day is celebrated on a Friday or Monday. This day is called Yama no hi day in Japan.
The purpose of the day is for people to appreciate the mountains and to become more familiar with all the blessings mountains offer.
This holiday was enacted by parliament on May 23, 2014 to be effective starting on the year 2016. The main push for the holiday came from the Japanese Apline Club stating that Shinto beliefs are shaped in nature as well as the mountians.