How to trick SharePoint into accepting today’s date in a calculated column.
Useful little trick, basically just switching the columns the calculated column refers to.
There is no defending myself against the accusation that this blog is getting too much SharePoint-centric. My only excuse is that calculated columns are way, way underused in SharePoint and are a mighty tool for various purposes. These sites compile almost all (i am joking, of course, i can only scratch the surface in this regard) there is to know about calculated columns: