Currently, a `date_expression` with `operation="in_range"` matches if the time is *after* start and *before* end. However if someone defines a range of 9AM to 10AM, they probably don't mean 9:00:01 to 09:59:59. Also, the logical meaning of "in range" would include the endpoints.
Since this is a change in behavior, it should be done at a minor or major series bump.