Yes, this is one thing that I've had a lot of difficulty with when trying to implement a reliable ISO parser. I've found that Python is one of the worst offende

Yes, this is one thing that I've had a lot of difficulty with when trying to implement a reliable ISO parser. I've found that Python is one of the worst offenders with this, as by default the datetime classes have no concept of tz, and it is significantly more difficult to attach tz info to a Python date. (Loosely mentioned in the article).