Is it possible to perform calculations with dates?

Is there a trigger that can calculate DATE changes?

It is possible to calculate the difference between two dates or calculate another date using update/calculate form field value conditions:

https://www.jotform.com/help/286-How-to-Pass-Field-Value-to-Another-Field

If there is a specific calculation you are trying to achieve, let us know and we will be happy to help with what we can.

Yes, I have two date fields near the bottom of my form.  I want to take the ONE date, add 30 days IF a certain field was filled out, and add it to the other date.  I have it set up , but it does not work.

I set up a quick example form to show you how it would work:

https://form.jotform.com/63367427084966

An example condition would look like this: