Wow, not sure how I missed that. I think inclusive ranges are easier to understand here.
Changed to
"abcdefg"[4..-1] returns "efg", since e is the character at index f, and f is the character at index -1, the last character. Halfway ranges also work, so "abcdefg"[..-2] returns all but the last character, and "abcdefg"[3..] returns everything from index 3 on