issue closed -> change "due date" to today / now

When I close an issue (today) which had a "due date" of tuesday next week, the "due date" remains the same - also in the gantt Chart.

I've altered the issue Status workflow to set closed to a "% done" of 100% - but this isn't quite what I want.

Is there a "Standard" way of doing this. e.g. set "% done" to 100% but ALSO set "due date" to today automatically. (this should also have the effect of altering "succeeding" Tasks in the gantt Chart.