XML Schema Part 2, Section 3.2.7.1, last paragraph: "Time periods, i.e. specific durations of time, can be represented by supplying two items of information: a start instant and a duration or a start instant and an end instant or an end instant and a duration"
------------- Actually, I interpreted that as being a recommendation to use two distinct attributes to convey an interval. Such as: <Vacation start="2000-01-19T13:00:00" duration="PT1S"/> <Vacation start="2000-01-19T13:00:00" end="2000-01-19T13:00:01"/> I believe my interpretation is consistent with the intent of the authors, however on review it could be more explicit.
