In a paragraph in a 1966 German book I’m translating, the author on describing the German sense of humor during hard times writes:
Unsere Väter muß einigen Spaß vertragen. Im Angesicht von Weltkriegen, Inflationen, Wirtschaftskrisen, schwarzen Freitagen , Not und Tod. Die deutsche Geschsichte im Spiegel des Witzes ...
[Our fathers must have some fun, in the face of world wars, inflation, economic crises, black Fridays , distress and death. The German story [is] in the mirror of the joke; ...]
After a bit of research I think that the connotation of “black Friday” in its 1966 context refers to the date of the East German government's announcement over the radio on Friday, August 10, 1961, that it was going to build a wall in Berlin which would separate the DDR’s sector in Berlin from the Allied sectors of that city.
Is my assumption on the meaning of the “black Friday” phrase correct?