I suspect few of us would be sure about the date this type of weight was made and whether to call it Bohemian or Czechoslovakian or something else.
The term "modern" is often used as a simplified way to distinguish 19th century from 20th century items. But when we consider the paperweight definitions of "classic" and "post-classic" the line of separation moves back into the 19th century (at least for most things).
If we think in terms of "Classic / Post-classic" periods, then "Modern Bohemian" presumably means c1870s/1880s to 1939 (with an interrupt for the war years iof 1914-18). If we think in terms of 19th or 20th century (being one of a few generalised views of "antique / modern") then "Modern Bohemian" must only mean 1900 - 1939. But ...
Peter Von Brackel, in his book, Paperweights, Historicism, Art Nouveau, Art Deco, 1842 to Present (published 1999), classes many of the illustrated weights of a similar style with overall faceting as "Bohemia / Czechoslovakia 1910 - 1930". (So what happened in the period 1900 - 1909? I wil have to read the book again to see if there is a simple answer to that!)
For some items, Peter extends the end date to 1939. For other items he includes another option for place of manufacture, such as "Silesia" or "Bavarian Forest".
Personally, I think Peter's generalised attribution and dating is about as good as it gets. Unless anyone can confirm anything more specific.