If you want a field with a value that is 122 days out from a given date field just create a calculated field such as the one in my screenshot below. This is just standard SharePoint functionality.
Rules are used for validation and formatting of Nintex form controls, but not for any calculations.
Your requirement is to show the "request completion date" as per the selected request date, I would suggest to use "Calculated Field" control on your form to show that date as shown below.
1. Place a "Calculated Field" next to your "Requested Date" control
2. In "Calculated Field" settings --> create formula for adding 122 days.
I'm curious why you paste screenshots and questions in a word doc. You can paste screenshots right in your post. Putting them in a word doc in the original post makes it hard to follow the thread.
if you use calculated value control, it can calculate date as you need, but you can not edit edit/change value in calculated value control.
you have to decide....
I removed the "+" but still nothing happened. Thanks anyway. I didn't realize I could post screenshots until I saw that you and others replied in that way. I see now the insert an image option. Thanks for bringing it to my attention. thanks for the explanation do you know if I can use kwizcom after I publish the nintex form? Kwizcom lets set a date but overwrite it.