When documenting APIs, developers often link to ISO 8601 as the standard for computer-readable date and date-time format. Dates and times (and time zones!) are complicated. There are so many edge cases and pitfalls. I’m sure every developer has a battle story about them. It’s good to delegate that hard work to somebody else. So when an international body that everybody knows and trusts publishes such a standard, it’s no surprise all the API designers start referring to it.
