Question: When did Harwit resign?
About the article "National Air and Space Museum", section "Controversies".

Candidate passages:
Martin Harwit (born March 9, 1931 in Prague) is a Czech-American astronomer, author, and was director of the National Air and Space Museum in Washington, D.C. from 1987 to 1995.
His scientific work on Infrared astronomy as a professor at Cornell University is notable.
In 1994 he became embroiled in public debate when his work on the Enola Gay exhibit, celebrating the 50th anniversary of the 1945 Atomic bombings of Hiroshima and Nagasaki, was accused of being "revisionist history" for including Japanese accounts of the attack and photographs of the victims, and for presenting an exhibit script that critics alleged "depicted the Japanese as victims of a United States motivated by vengeance."
Two of the lines about the war in the Pacific became infamous: “For most Americans this war was fundamentally different than the one waged against Germany and Italy—it was a war of vengeance.
For most Japanese, it was a war to defend their unique culture against Western imperialism.” The immediately preceding two sentences did acknowledge that "in December 1941, Japan attacked US.
bases at Pearl Harbor, Hawaii, and launched other surprise assaults against Allied territories in the Paciﬁc.
Thus began a wider conﬂict marked by extreme bitterness."
Those lines, in turn, were immediately preceded by the following statements: Nonetheless, the controversy led to his being forced to resign from the directorship of the National Air and Space Museum.
It was revealed months later that while he was attempting to limit distribution of the planned exhibit to US critics, he was having the script translated and overnighted to officials in Hiroshima and Nagasaki asking for a "quick response". 
Exhibition controversy.
"Enola Gay" became the center of a controversy at the Smithsonian Institution when the museum planned to put its fuselage on public display in 1995 as part of an exhibit commemorating the 50th anniversary of the atomic bombing of Hiroshima.
The exhibit, "The Crossroads: The End of World War II, the Atomic Bomb and the Cold War", was drafted by the Smithsonian's National Air and Space Museum staff, and arranged around the restored "Enola Gay".
Critics of the planned exhibit, especially those of the American Legion and the Air Force Association, charged that the exhibit focused too much attention on the Japanese casualties inflicted by the nuclear bomb, rather than on the motivations for the bombing or the discussion of the bomb's role in ending the conflict with Japan.
The exhibit brought to national attention many long-standing academic and political issues related to retrospective views of the bombings.
As a result, after various failed attempts to revise the exhibit in order to meet the satisfaction of competing interest groups, the exhibit was canceled on 30 January 1995.
Martin O. Harwit, Director of the National Air and Space Museum, was compelled to resign over the controversy.
The forward fuselage did go on display on 28 June 1995.
On 2 July 1995, three people were arrested for throwing ash and human blood on the aircraft's fuselage, following an earlier incident in which a protester had thrown red paint over the gallery's carpeting.
The exhibition closed on 18 May 1998, and the fuselage was returned to the Garber Facility for final restoration. 
Controversy erupted in March 1994 over a proposed commemoration of the 50th anniversary of the atomic bombing of Japan.
The centerpiece of the exhibit was the "Enola Gay", the B-29 bomber that dropped the A-bomb on the Japanese city of Hiroshima.
Veterans' groups, led by the Air Force Association and The Retired Officers Association, argued strongly that the exhibit's inclusion of Japanese accounts and photographs of victims politicized the exhibit and insulted U.S. airmen.
Also disputed was the predicted number of U.S. casualties that would have resulted from an invasion of Japan, had that been necessary, after the museum director, Martin O. Harwit, unilaterally reduced the figure by 75% on January 9, 1995, at the height of the dispute.
On January 18 the American Legion called for a congressional investigation of the matter, and on January 24, 1995, 81 members of Congress called for Harwit's resignation.
Harwit was forced to resign on May 2.
Although the exhibit was "radically reduced" and criticized by the "New York Times" as "the most diminished display in Smithsonian history," the Air and Space Museum placed the forward fuselage of the "Enola Gay" and other items on display as part of a non-political historical exhibition.
Within a year, it had drawn more than a million visitors, making it the most popular special exhibition in the history of the NASM, and when the exhibition closed in May 1998, it had drawn nearly four million visitors.
On October 8, 2011, the museum was temporarily closed after demonstrators associated with the Occupy D.C. demonstration attempted to enter the museum.
Some protesters were pepper sprayed by museum security after a guard was pinned against a wall.
One woman was arrested.
On December 5, 2013, Smithsonian food workers protested about a living wage.
A journalist was detained for filming.
Awards Bruce Medal (2007) Named after him Asteroid 12143 Harwit  
When the war was over, Vignoles and others were put on half pay in 1816.
He sought alternative employment, although he did not formally resign his commission until 1833.