Mountain Day (山の日)2026 · Date · History · Messages
Japan’s Act on National Holidays, as amended by Act No. 43 of 2014, establishes Mountain Day on 11 August and states its purpose as providing an opportunity to become familiar with mountains and appreciate their benefits. The holiday took effect from 2016; 2020 and 2021 Olympic-year dates were temporary exceptions.
About Mountain Day (山の日)
Mountain Day (山の日, Yama no Hi) is a Japanese national holiday normally observed on August 11.
The Act on National Holidays describes its purpose as providing an opportunity to become familiar with mountains and appreciate the benefits they provide.
Why Mountain Day (山の日) matters
Mountain Day is a statutory national holiday, not an informal outdoor campaign. Its normal date and purpose are defined in Japanese holiday law.
The holiday can be marked through reflection, learning or time in nature; it does not require hiking, climbing or any activity beyond a person’s ability, access or local conditions.
History of Mountain Day (山の日)
Japan enacted Act No. 43 of 2014 on May 30, 2014, adding Mountain Day on August 11 to the Act on National Holidays.
The amendment took effect on January 1, 2016, and government guidance describes Mountain Day as being established from 2016.
Special Olympic and Paralympic legislation temporarily moved Mountain Day in 2020 and 2021; those dates were exceptions rather than a permanent change to the August 11 rule.
How the observance developed
This timeline uses documented milestones from reviewed sources. Missing stages are left out rather than guessed.
Seishirō Etō and nine other House members
The House of Councillors bill record identifies Etō Seishirō and nine others as the member-proposers of the bill.
National Diet of Japan
Act No. 43 of 2014, Act Partially Amending the Act on National Holidays
First documented observance
The 2014 amendment took effect from January 1, 2016, and current government history states that Mountain Day was established from 2016 on August 11.
Mountain Day was temporarily observed on 10 August 2020.
Government of Japan / National Diet · Tokyo Olympic and Paralympic special holiday provisions
Mountain Day was temporarily observed on 8 August 2021, with 9 August becoming a substitute holiday.
Government of Japan / National Diet · Tokyo Olympic and Paralympic special holiday provisions
Government of Japan
The Cabinet Office maintains the statutory national-holiday definition and current national holiday calendar.
What the evidence establishes
Confirmed institutional roles and milestones are shown first. Details that could not be established from the reviewed sources are listed separately below.
2 fields not established in reviewed sources
Later institutional actions
Later recognition, renaming, mergers or date changes are kept separate from original establishment.
How to Observe Mountain Day (山の日)
Learn about the mountains, watersheds, forests or protected landscapes near you.
Visit a museum, visitor center or reliable public resource about mountain ecology and culture.
Spend time outdoors only where access, weather, health and local guidance make that appropriate.
If outdoor activity is not practical, mark the holiday through reading, photography, art or appreciation of mountain environments.
Mountain Day (山の日) Facts
Mountain Day is normally August 11.
It was added to Japan’s holiday law by Act No. 43 of 2014.
The holiday took effect from 2016.
Its statutory purpose is to provide an opportunity to become familiar with mountains and appreciate their benefits.
The 2020 and 2021 Olympic-year dates were temporary exceptions.
Mountain Day (山の日) Messages
Celebrate mountains in a way that fits your access, ability and local conditions.
May Mountain Day be a reminder of the many ways mountain environments support life and culture.
Topic and context
What this page does not assume
- Keep the source-defined country, community, organizer or institutional scope; do not silently broaden it.
- Do not treat the title alone as proof of government recognition or public-holiday status.
- Do not add a creator, founding story or origin claim unless the supporting evidence establishes it.
- Confirm the date again before carrying it into a new year.
Evidence & sources
Sources used across the guide are gathered here. Labels show how each source supports the page, and contextual references are kept separate from primary evidence.
Act No. 43 of 2014 / House of Representatives
Cabinet Office, Government of Japan
Government Public Relations Online
House of Councillors legislative history
Cabinet Office, Japan — National Holidays (opens in a new tab)
Government Holiday Calendar
Government Public Relations Online — national holidays and Mountain Day history (opens in a new tab)
Government History
House of Councillors, Japan — bill history for Act on National Holidays amendment (opens in a new tab)
National Legislative History
House of Representatives, Japan — Act No. 43 of 2014 (opens in a new tab)
National Legislation
Understand it, compare it, then explore further
Start with the most common factual questions, then compare closely related observances and explore useful connections.
Frequently asked questions
When is Mountain Day (山の日)?
11 August The documented recurrence rule is: 11 August under the Act on National Holidays; temporary 2020 and 2021 Olympic-year exceptions are historical only..
Does Mountain Day (山の日) fall on the same date every year?
Yes. It uses a fixed annual date unless stronger evidence changes the pattern.
Is Mountain Day (山の日) an official public holiday?
Within the reviewed scope, it is identified as Japan / statutory national holiday. That status is not automatically extended to other countries or jurisdictions.
Who established or recognizes Mountain Day (山の日)?
The reviewed sources identify National Diet of Japan as the proclaiming or establishing body. The proposer or originator is recorded separately as Seishirō Etō and nine other House members. Current facilitation or coordination is recorded as Government of Japan.
Is Mountain Day (山の日) international or country-specific?
This observance is specific to Japan. Its fuller verified scope is: Japan / statutory national holiday.
How is this page verified?
The factual information is checked against reviewed sources, including the date pattern, scope and institutional history. This page was checked on 2026-09-25.
When is Mountain Day in Japan?
The normal statutory date is August 11.
When did Mountain Day become a national holiday?
A 2014 amendment created the holiday, effective from 2016.
Why were the dates different in 2020 and 2021?
Special legislation temporarily shifted several Japanese holidays around the Tokyo Olympic and Paralympic schedule; those shifts did not replace the normal August 11 rule.
Do people have to hike on Mountain Day?
No. The holiday’s purpose concerns familiarity with and appreciation of mountains; participation can be educational, reflective or outdoors, depending on access and conditions.
Other observances on August 11
These observances are also listed on August 11, 2027.
Chad Independence Day
Chadian government sources identify 11 August 1960 as the date of independence and continue the national commemoration in 2026.
World Calligraphy Day
A calligraphy museum account states that World Calligraphy Day was established in 2017 by Manuscript Pen Company with the Pen Museum and is marked on the second Wednesday of August.
World Steelpan Day
A/RES/77/316