You can, as a super user, turn on or off the need for approval for changing due date on actions, on a modular level.
To access this setting simply go to Menu -> Super -> Modules -> [Relevant module] -> Admin tab.
At the bottom of the page you will find the toggle to turn this on or off.
With this setting turned on any change to due date will be sent to the action creator for approval. If it is off, any changes to due date are automatically approved.