Thank you for your comment, Bram!

Yes, I fully agree with you, however, I saw many APIs claiming (full) support for ISO 8601, but not accepting the less used formats. What I aim to achieve with this article is that the developers will either make sure that they support what they claim they support or they change the documentation.

Also, using libraries like Moment can add unnecessary complexity, and also runtime cost. I’d argue that most people actually do not want to support to whole breath of the standard.