Date manipulation

Hi everyone,

I'm a newbie in dashboard reporting tool so I apologize if you may find my question too simple. :)

I have a date field that has a value of 1/1/2016 and I wanted to manipulate my date field and add 30 days or 15 days to it. how can I do that?

so, 1/1/2016 plus 30 days would be 2/1/2016.  that would be my expected output.

Please share your thoughts.