What does the dash on a tombstone represent?

Answer 1

The dates are the person's birth and death dates. The dash signifies the time in between. It's like saying "this person lived from <birth date> until <death date>".

Actually the dash would not mean "until" since the word until would imply that the death occurred prior to that date happening. The dash would mean he lived "to" the point in time, the word "meaning" not before and not after that date, but not specifying a time.