How to do date calculations inside a scoped app

[gnewuser]

I have a scoped app with 2 date fields and an integer field on a form. I would like to find the difference between these 2 dates and populate the integer field with the difference which would be in days.  Looks like I cannot use glidedatetime because this is client side.

How can I find the difference between 2 dates in terms of days in a scoped app.

Any help appreciated.

Thanks so much

[gnewuser]

Thanks but would this work inside a scoped application?