How to create total number of nights

I would like to add a field in which will show the total number of nights based on the previous two fields: One arrival, the other is departure. Please advise.

That can be achieved using date fields and calculation.

However, this widget is created to perform such function.

https://widgets.jotform.com/widget/dates_difference

Here's how:

1. Add the Dates Difference widget in your form

2. Add a Form Calculation widget

3. In the calculation widget, add the date difference field to get the calculated days

Demo: https://form.jotformpro.com/71008489422961