I was going to say that this has a weakness in testing because you can't `assert(end > start)` without knowing which is which because `assert(later > sooner)` w

I was going to say that this has a weakness in testing because you can't `assert(end > start)` without knowing which is which because `assert(later > sooner)` will always be true but then I guess you'd have input (and other) validations before it got to that point anyway.