No, ≈ is used for approximation, ~ is just the most similar ASCII character, and it became ingrained by people used to using old computers. Just like * is not a multiplication sign, but × is.
In other words, tilde is used for approximation just like the asterisk is used for multiplication and “literally” is used figuratively. We can argue over those uses being correct or incorrect, but they are used like that.
Thus I agree that using tilde for numeric ranges would be confusing. Might as well just use a hyphen, which is easier to type and most people won’t notice the difference from the correct character (en-dash).
Using that form of reasoning, it could be claimed that, say, “espresso” is pronounced ”expresso”, because some people do pronounce it like that.
But that would be disingenuous, since “is pronounced” does not generally mean “is sometimes, by some people, pronounced”, but “is supposed to be pronounced” or “is properly pronounced”. The same goes for “tilde is used for approximation”; no it isn’t. If would be different if scbrg had written “tilde is sometimes used for approximation”; it would have indicated a possible interpretation of the first meaning, and not the second.
> If would be different if scbrg had written “tilde is sometimes used for approximation”;
Oh, dear lord. I apologize for leaving out this very important word. I thought it was fairly clear that I didn't mean it was the only symbol used for approximation, pretty much like how, I don't know... nothing is the only thing used for anything.
Whatever phrase, symbol, word or tool in general you find, you can be fairly certain that there's something else that could be used instead.
In the really real world, people tend to use the symbols that are easy to type with their keyboards. Ironically, this is a bit like what TFA complains about; people always use the hyphen that's available with one keystroke when in fact they "should" (for some arbitrary value of "should") use a handful of different ones. And they use tilde for approximation, because nobody knows how to type a fucking ≈. You'll also note that they use " when they "should" have used “, ” or any of the umpteen other variants of quotation marks.
When it comes to ambiguity, which was what this sub thread was about, how things are often used is actually quite important. Because, you know, it's what people actually write that you have to disambiguate, not what they should have written.
Using × or ∙ for multiplication is, IIUC, a cultural differentiator – just like English uses . as a decimal separator, but many Europeans use , for the same purpose. But in Unicode, × is “MULTIPLICATION SIGN” and ∙ is “BULLET OPERATOR”, and * is more visually similar to × than ∙, so I assume that’s where it originates.
The sentence as you wrote it could be misinterpreted as "the conflict spanning the years 1939 to ca. 1945...".
Had you used a dash/hyphen/minus/whatever nobody would be likely to misinterpret that as "the conflict spanning the years minus six..."