I'll just say what I've said several times before to others: Instead of making assumptions (including the assumption that the wisdom seeker knows to rigorously test code) and throwing code out there that will (silently!) break when the assumptions aren't met, there are several alternatives, IMHO better ones:

• Clearly documenting the assumptions.
• Coding defensively, i.e. the code dies if the assumptions aren't met.
• Applying Postel's law and accepting a wider range of inputs. (E.g. accept single digits in every field of the datetime.)
• Asking the wisdom seeker for clarification.