Hi,
Costumes can be a difficult thing to date, as they are, well...costumes! Judging by the general look of the graphics, as well as the women's hair style, and the 1 woman's headress/bandeau, it could be earlier than the 1920's. The hair styles and head gear could be as early as 1913 to 1914. If I had to pin it down, I would say circa 1917-1918 just based on the general vibe I get.