How to create datetime string in soapui using groovy with +10 days or -10 days

Hi All,

So far in my suite property have used ${= new Date().format('yyyy-MM-dd')}

this will help us to get the current date and time 

but now I need to get the date current date + 2 or -2

I tried like

So far in my suite property have used ${= new Date().format('yyyy-MM-dd, +2')}

but it's not working.

Please share the  imput