This may sound a little random, but one of the things that varies most between APIs is date and time formats. Many API implementations come up with their own. L

This may sound a little random, but one of the things that varies most between APIs is date and time formats. Many API implementations come up with their own. Looking at what the date format is tells you how much thought has gone into looking the API design. Hopefully it one of the ISO 8601 options, otherwise I'd start looking more carefully at the documentation