I want to show a date 8 weeks before the date given in my form for "arrival Date"

I have tried every format of calculation I can think of but they don't return the needed date.  Help would be much appreciated

KJohn westbrook

It is possible to achieve what you want, but you will need to use the basic date picker field instead of a widget, this way you will be able to take the selected date and either increase or decrease it. 

You will need to add an additional date picker field to your form and you will use conditions to set the date on this secondly added date field. 

56 is the number of days that will be subtracted from the selected date on the first date field, you could change this value if you want. The result can be seen here: https://form.jotformpro.com/71654628289974 

Feel free to clone my form and see what I did, this guide will help you to clone my form: How-to-Clone-an-Existing-Form-from-a-URL

Hope this helps.