Change "defined" in description to "specified" (according to "effectivity"). Example 1 is rather a Note; rephrase it to: Events may be at the planning phase to bound a dated effectivity interval". Add another, clearer example. Are there "events" without dates, or does "events" really mean "event dates" (which then means it can be removed from the description)? If not, the label needs to be changed.
The definition;
"effectivity for which the domain of applicability is defined as an interval of time bounded by dates or events"
should be;
"effectivity defined as an interval of time bounded by dates (or events)"
because the phrase "domain of applicability" is already used in the definition of effectivity
A better example; "The dated effectivity for version b of product 123 was between 2013-02-22 and 2013-04-11"