I found myself stuck with a silly problem.
There are heaps of museums and galleries in Tokyo, but most are closed on Mondays except for when Monday is a public holiday.
The problem - finding some museums and galleries that are open on Mondays.
So far I've found:
National Museum of Nature and Science (visited last year and closed on July 9)
http://www.kahaku.go.jp/english/ http://www.kahaku.go.jp/english/news/20 ... index.html - closed July 2-6, 9 and 17, September 3, 10, 18 and 24, October 9, 15, 22 and 29
Science Museum
http://www.gotokyo.org/en/kanko/chiyoda/spot/11.html http://www.jsf.or.jp/eng/charge/ - closed Wednesday
Yushukan at Yasukuni Jinja Shrine
http://www.gotokyo.org/en/kanko/chiyoda/spot/s_471.html http://www.yasukuni.or.jp/english/precinct/index.html (appears to be open every day)
21_21 Design Sight
http://www.gotokyo.org/en/kanko/minato/spot/s_881.html http://www.gotokyo.org/en/kanko/minato/spot/s_881.html - closed Tuesdays, New Year Holidays, Changeover periods
Jusaburo
http://www.gotokyo.org/en/kanko/chuo/spot/s_311.html http://www.jusaburo.net/jusaburo.html - closed Wednesday
Minato City Local History Museum
http://www.gotokyo.org/en/kanko/minato/spot/s_405.html http://www.lib.city.minato.tokyo.jp/muse/e/guide1.html - closed Sundays, Holidays, and the third Thursday every month. (If the Thursday is a holiday, closing will be on the previous day.) Year-end and New Year's holidays (Dec. 29 - Jan. 4). Special operations period (about 2 weeks from the middle to the end of June). Special closing date (about 2 weeks before and after the special exhibition programs and for facility improvement).
Mori Art Museum
http://www.gotokyo.org/en/kanko/minato/spot/194.html http://www.mori.art.museum/eng/info/access.html - closed when no exhibitions are being held
[edit - I received a reply from the gotokyo.org site and they suggested the following]
Miraikan
http://www.miraikan.jst.go.jp/en/ - closed every Tuesday, and during the period from December 28, 2011 to January 1, 2012. *The Museum will be open on the following Tuesdays: July 24, July 31, throughout August, 2012.
*The Museum may close temporarily for facility maintenance.
TARO OKAMOTO memorial museum
http://www.taro-okamoto.or.jp/guide.html - Closed Tuesday (In the case of public holidays the museum is open) and maintenance (12/28 ~ 1/4) New Year
MORI ART MUSEUM
http://www.mori.art.museum/eng/index.html - as listed above
The National art center
http://www.nact.jp/english/index.html - closed on Tuesdays, the year-end through the New Year's holidays
Suntory museum of art
http://www.suntory.co.jp/sma/ - no permanent exhibitions, check site for current exhibitions
(note that the Mori Art Museum, National Art Center and Suntory Museum of Art and 21_21 Design Sight are close to each other, see:
http://www.nact.jp/english/access.html and
http://www.2121designsight.jp/en/access/ )
The tedious procedure for finding places open on Monday seems to be:
start at gotokyo.org:
http://www.gotokyo.org/search/en/genre? ... 1&status=1
look through each museum and gallery listed, then go to its own website and either look for an English language page or google translate pages until one finds the opening hours.
Going down the list, places that appear to be closed on Mondays are:
Communications Museum Teipark
http://www.gotokyo.org/en/kanko/chiyoda/spot/s_340.html http://www.teipark.jp/e_ac.html - closed Monday except for public holidays, then closed on Tuesday
Idemitsu Museum of Arts
http://www.gotokyo.org/en/kanko/chiyoda/spot/5.html http://www.idemitsu.com/museum/honkan/index.html - Closed Monday (The Museum will be open when Monday is a national holiday.), the year-end and New Year holidays, and the change of exhibits.
JCII Camera Museum
http://www.gotokyo.org/en/kanko/chiyoda/spot/69.html http://www.jcii-cameramuseum.jp/ - Closed Mondays (In case Monday is a National Holiday, the museum will be open and be closed the following day), the beginning and end of the year, and other dates determined by the museum.
Mitsuo Aida Museum
http://www.gotokyo.org/en/kanko/chiyoda/spot/1384.html http://www.mitsuo.co.jp/museum/info/index.html - closed Mondays (In the case of national holidays and public holidays the museum is open) and closed for IMF meetings.
National Showa Memorial Museum
http://www.gotokyo.org/en/kanko/chiyoda/spot/s_443.html http://www.showakan.go.jp/pdf/showakan_en.pdf - closed Mondays except for public holidays, then closed on Tuesday
New Otani Museum
http://www.gotokyo.org/en/kanko/chiyoda/spot/72.html http://www.newotani.co.jp/group/museum/index.html - closed Mondays except for public holidays, then closed on Tuesday
Shokei-kan Historical Materials Hall for Wounded and Sick Retired Soldiers
http://www.gotokyo.org/en/kanko/chiyoda/spot/191.html http://www.shokeikan.go.jp/sub_menu/english_page.html - closed Mondays (or Tuesdays when Monday is a holiday or deferred holiday)
The National Museum of Modern Art, Tokyo
http://www.gotokyo.org/en/kanko/chiyoda/spot/40345.html http://www.momat.go.jp/english/topics/i ... l#20110517 - closed on Mondays (except July 18)
Yonbancho Chiyoda City Museum of History and Folklore
http://www.gotokyo.org/en/kanko/chiyoda/spot/1589.html ?? (can't find opening hours)
Bank of Japan Currency Museum
http://www.gotokyo.org/en/kanko/chuo/spot/s_365.html http://www.imes.boj.or.jp/cm/english_ht ... vi2_en.htm - closed Mondays
Bridgestone Museum of Art
http://www.gotokyo.org/en/kanko/chuo/spot/40389.html http://www.bridgestone-museum.gr.jp/en/ - closed on Mondays (Mondays that fall on holidays will be open)
Button Museum
http://www.gotokyo.org/en/kanko/chuo/spot/40395.html ??? (no web site given and no hours of opening given)
Mitsui Memorial Museum
http://www.gotokyo.org/en/kanko/chuo/spot/200.html http://www.mitsui-museum.jp/english/english.html - closed Mondays(except 7/16, 8/13), closed 7/17; If Monday is a national holiday, the museum will be open on Monday and closed the following day.
Musee Hamaguchi Yozo: Yamasa Collection
http://www.gotokyo.org/en/kanko/chuo/spot/s_407.html http://www.yamasa.com/musee/info/ - closed days not clear from google translate of Japanese info page
Pen Station Museum & Cafe
http://www.gotokyo.org/en/kanko/chuo/spot/40255.html ?? - no official website given and no days/hours of opening on gotokyo.org site
TOKYO KITE MUSEUM
http://www.gotokyo.org/en/kanko/chuo/spot/40331.html ?? - no official website given and no days/hours of opening on gotokyo.org site
Advanced Technology Exhibition Hall@TEPIA
http://www.gotokyo.org/en/kanko/minato/spot/40326.html http://www.tepia.jp/exhibition/pdf/h24_leaf_en.pdf - closed Mondays (Open when Monday falls on a holiday, but closed on the following Tuesday.)
Advertising Museum Tokyo
http://www.gotokyo.org/en/kanko/minato/spot/s_259.html http://www.admt.jp/en/guide/schedule/index.html - closed Monday (closed Sunday and Tuesday if Monday falls on a holiday)
Hatakeyama Memorial Museum of Fine Art
http://www.gotokyo.org/en/kanko/minato/spot/40375.html ?? (no web site given and no days/hours of opening given)
Institute for Nature Study, National Museum of Nature and Science, Tokyo
http://www.gotokyo.org/en/kanko/minato/spot/40500.html (no web site given and no days/hours of opening given)
Shitamachi Museum
http://www.taitocity.net/taito/shitamac ... glish.html - closed Monday (Open if it is a holiday and closed the next day)
Panasonic Electrical Engineering Museum in Shiodome
http://www.gotokyo.org/en/kanko/minato/spot/s_307.html http://panasonic.co.jp/es/museum/en/access/ - closed on Mondays (excluding holidays), New Year holidays, museum summer holidays, and during changes of exhibits.
To be continued...