Interesting article. Mal-formed dates are the bane of my professional life; often this goes hand-in-hand with Excel data and/or lack of user discipline and validation.

I've experienced date-related issues whilst working around the globe and in my experience, the US has the worst practices, whilst continental Europe has better disciplined users and validation. Whenever I am involved in the design/ETL phase of a project concerning data with dates, I go that bit extra to ensure that we have a least understood the magnitude of the problems around storage of such data. I favour always referencing dates in full ISO format, but it is important that people understand the format being used, rather than assume based on their locale. Where ambiguity can sneak in, I will use a format that is explicit and localised.

One thing I did notice about the article, however, was the use of yy for year formats. It would seem that the "Y2K Bug" has not taught us very much afterall!