Message
foo
must be an ISO-8601 date-time
Explanation
Invalid date-tie.
Solution
The value specified must adhere to the ISO 8601 Date and time format.
An example of a valid ISO8601 Date-time: 2002-10-02T10:00:00-05:00
Not clear? Disagree?
You might be able to find help in one of these fine resources.