My school has a rolling enrollment, as such I have a number of students who joined mid way through content at varying places. In the new grade book, I saw a handy late submission box, and checked it thinking it would make my life much easier by automatically providing zero's for missing assignments. Well it went back and put in zero's for every not graded assignment I had, that were exempt because the student hadn't joined us yet.

Is there a way to change the status of multiple assignments at once (like highlight 20 assignments and mark them all excused)? Or perhaps to set a begin date for each student, where it figures this out automatically.