Hyphens are not meant to be used for ranges (e.g., 10-12, 1967-
1971). Dashes are used for this purpose. However, given that the hyphen is so easy to find on a keyboard, hyphens have become acceptable for ranges. Only a very strict grammar pedant would pull you up for using hyphens. If this were to happen, you could make a good case for the pedant being out of date.