InfoPath Dev

Thank you. I'm really stuck with this one, can't wait to see what you will come up with.

Hi all, First I have to say that I'm new to Infopath 2013 and this forum has been really helpful! I have tried to find a solution myself and on other forums without success. So, I have 3 fields : a Start Date, a duration with a drop down to select days, months or years and a Finish date. My aim here is when I fill up the start ...