Good Design is Imperfect Design, Part 1: Honest Names
I disagree about &quot;plus&quot; in the JodaTime example.  The month addition with corner cases did exactly what I expected because the whole library has been polished to &quot;do what a normal human would do, most of the time&quot;.  A normal human would not suspect Jan + 1 month, is any month other than Feb.  However I suspect, not even reading the documentation, if it were fed 30 or 31 days, rather than &#x27;1 month&#x27;, it would also do exactly that, and mostly give dates in March.