Board Thread:The Gatehouse/@comment-66.60.76.2-20140123140944/@comment-89.154.99.228-20140123215842

Click the little pencil on the right corner of your to do, which will lead you to edit it. Among other things, you can add a due date there. (Third text box, click it nd a calender will pop up for you to select the date."

I'm not sure whether it influences how slowly or rapidly it makes it turn red, though...

I do know you don't have to worry about it killing you! To-Do's don't decrease health when you don't do them. Only dailies do that.