I could not read back the value when I just tried, but I am not that experienced with applescript. Maybe someone else can get it to work. I was wondering if after changing the defer date you could select the Omnifocus task at the top of the list. I have a several little scripts to defer items but one I run one of these scripts to defer the time, I would like the top item on the list to be selected (I commonly do this to items in the defer perspective. Is there any way to do this?