Thanks... I will give a try.

Would this functionality be able to applied to the K2 Calendar Module? So it shows the date the item will close on the calendar, rather then the date it was added?

It is a little more complicated for the calendar. This will have to be added in the module's core file. If you want to make the modification yourself the file that includes the calendar functions is the helper.php file.
Make sure to take a backup of your file before any K2 update since the changes you make will be lost.

I'll take a look, but my skills at php are VERY limited...

Thanks a million!!!

You're welcome.