It doesn't matter. It was decided on June 26th because 1987 held a ministerial conference on "Drug Abuse and Illicit Trafficking" in Vienna from June 2nd to 26th, with 3000 representatives from 138 countries and regions attending. The conference put forward the slogan "Love life, don't take drugs". At the same time, in order to further arouse the attention of countries and regions to the drug problem, call on people all over the world to resolutely crack down on drug attacks and drug-related crimes, and also to commemorate this significant international anti-drug conference, at the end of the conference, the delegates unanimously suggested that June 26th of each year be designated as the International Anti-Drug Day.

June 26th is the day when the meeting ends.