Hi,
I had a look around and there really isnt anyting in Nintex Workflow to format a date unless you get complex and write a web service to do it and then call the web service.
You can easily acheive this by using a Calculated Value control on a Nintex form with the FormatDate runtime function and save that on a column and then use the workflow to read the column and put it into a variable. I know that this does not help if you want to use the date at the time of running the workflow.
