In the Hyouka anime, when did the cultural festival revolution led by Jun Sekiya take place?

Judging from the anime, the time should be 1967, which is the 42nd year of Showa, which is called forty-five years ago in the anime.

The first is the preface of Hingguo No. 2

The preface states that the time occurred one year ago, and the preface time is October 13, 1968, so the entire The incident occurred in 1967.

Then if you want to know the specific time, look at "The Development Trajectory of Kamiyama High School in the Fifty Years"

From the explanation in the anime:

The cause of the incident It was on April 12, 1967, that the principal made a declaration of emphasizing academic ability "not to stop at a private school in a deserted village" and wanted to shorten the cultural festival;

Then on June 30, the "Cultural Festival after school" was held Seminar";

And a cultural festival was held from October 13th to 17th.

Look again at the article in "Unity and Salute"

The article "...will never succumb to the brutal violence of conservative forces. Citing the struggle in June last year as an example..." mentioned in the article The fight is in June.

So the time point to consider is as follows

April 12, the principal’s declaration of emphasis on academic ability "cannot stop at a private school in a deserted village"

June 30 Cultural Festival Seminar after school on October 13th-17th

Cultural Festival on October 13th-17th

Speculation: After the principal put forward the declaration, dissatisfaction began to appear among the students, from posting slogans to going on strike , and then developed into a joint protest demonstration by academic and artistic societies in early June, with Jun Sekiya becoming the ostensible leader. The protests reached their peak at the end of June, and a fire broke out later. The school held a seminar on June 30. At the meeting, it was decided to cancel the shortened cultural festival and expel Jun Sekiya after the cultural festival.

The above speculation is just a possibility. There seems to be no specific time of the fire in the anime. Judging from the current situation, if the school building catches fire due to your fault, it is basically impossible for you to stay for 3 months. Above, you may be fired the next day. Therefore, there is another possibility that the school put forward its opinions in April, officially issued the notice after the seminar in June, and the struggle was held between July and September. It was called the "June Struggle", probably because the struggle was launched at the end of June, so it was named so, but it was a bit forced.