Date data type conversion into String data type

Hi to all,

I want to take the current date in my graphical mapping and to substract "2" from this date. I use the "currentDate" function to get the current date and the "substract" function to substract the "2" value from my date. I format the date only with "yyyy" format model. My problem is that the currentDate function give me an output of type "Date" and not String, thus I'm not able to use any other functions, as "substract", that take a String value as input.

How can I solve this problem?

Thanks to all!