User blog comment:Chaotic38/Estimated Choices Timeline/@comment-3452092-20190306020948/@comment-3452092-20190319113117

At the end of The Freshman, Book 3 Madison, Logan, Tripp, and Edgar tell you that they are going on a cruise. This happens in the Rules of Engagement series.

Endless Summer, Book 1 starts on June 1, which is spring, but you are right, Rules of Engagement, Book 1 and at least part of Book 2'' do happen before it, so they must occur in May or something which makes them start in Spring as well. Interesting.