How does Japan mark Environment Days?
みどりの日
- Local date
- May 4, 2027
Midori no Hi — Greenery Day — is one of Japan's sixteen national holidays, set out in article 2 of the Act on National Holidays (Act No. 178 of 1948): 4 May, for "becoming familiar with nature, being grateful for its blessings, and cultivating a rich heart." Article 3 is the sentence that separates Japan from the other six countries here: national holidays are days off, full stop. The origin, though, has nothing to do with nature. When the Act was written, the Emperor's Birthday fell on 29 April, the birthday of the Showa Emperor. After the accession in 1989 the Emperor's Birthday moved to 23 December, and the 29 April slot was renamed Midori no Hi in that year's amendment so that the holiday itself would remain. A further amendment in 2005 turned 29 April into Showa Day from 2007 and moved Midori no Hi to 4 May, inside Golden Week. The Cabinet Office also runs a Greenery Month from 15 April to 14 May and a Midori Academic Prize.
環境の日
- Local date
- June 5, 2027
Japan's other environment day is not a holiday at all. Environment Day falls on 5 June under article 10 of the Basic Environment Act (Act No. 91 of 1993): the day exists to deepen public and business awareness of environmental conservation, paragraph 2 fixes the date, and paragraph 3 asks only that national and local government "endeavour to carry out projects befitting its purpose" — a duty to try, not a day off. The Ministry of the Environment designates the whole of June as Environment Month; the FY2026 programme was announced by the Minister's Secretariat on 28 May 2026. The date carries a detail worth keeping: it marks the UN Conference on the Human Environment that opened in Stockholm on 5 June 1972, and the United Nations designated 5 June as World Environment Day on a proposal from Japan. The 5 June that Taiwan, Indonesia and Brazil each use later on starts here.
What is this topic?
Environment days almost never come with a day off. Across these seven countries there is exactly one exception, and it exists by accident: 4 May in Japan, Midori no Hi, is a statutory public holiday under article 2 of the Act on National Holidays. It began as the Showa Emperor's birthday on 29 April; when the throne passed in 1989 the birthday moved to December and the empty 29 April was renamed Greenery Day so the day off would survive, then shifted again to 4 May in 2007. Everywhere else the environment day is written into a statute, a decree or an assembly resolution — and the same instrument says nobody stops working.
Sources and dates
Dates follow local time zones, calendars, and official notices. Check the source when a date is estimated or locally variable.