Surprisingly I could not find a blog that told me how to change the date format in Dynamics CRM 2013.
There are plenty of blogs which say how to di it for CRM 2011 but I already knew that. So what has happened to the Personal Options that was accessible from the File menu?
You will find it in the top right hand corner as the little settings wheel. that will give you access to the Options and the About box. Once you have the Personal Options dialog open, then you change the date as you did before. Go to the Formats tab, and change the current format to whatever you want.