Change Date & Re-Change Program

thank you to whoever gets back to me on this. So I am trying to write a little something that will

• change the date in Windows to show: 4-15-2015
• launch an .exe
• pause for either a minute or a keystroke from the user
• change the date back to what ever the actual date is

I was using a .bat file, and I was able to change the date to 4-15-2015, launch the .exe, and use "pause" to wait until a Keystroke, then I got stuck with figuring out how to take the original date and change the "4-15-15" back to the original date.

My .bat looked like this:

@echo off
Date 4-15-2015
Start (path To exe)

and then I didn't know how to put it back to whatever it was when I originally launched the application. So if I launched it on May 8th I would want to put the displayed windows date back to may 8th, if I launched it on 7-12-15 I would want to put it back to 7-12-15. Anyone have any ideas? Should I use another lanugage? And if so, how would I write this? I had a thought of reading the initial date and keeping it as a variable... but I don't know how to using a .bat file. Thanks to any help.