It works on your PDF, but if I copy that subform into my document, it gives a number in the 44,000's ?

Thanks kprokopi - the script works fine on the form you sent. But when I copy and past those 3 fields to my own form, it does't work and I get a huge number! Yours: https://imgur.com/gallery/9ucexUm Mine: https://imgur.com/gallery/NLojPoo I also looks like the date format is different in the 2nd box...

CHI is actually a text field already! I'm not sure why I said it was a numeric field, sorry! I actually got it working on the advice of radzmar, though I still need to set a validation pattern to make sure that the user enters a 10 digit number.

Thanks for that! But with a current date of 28 August 2020 and an field 2 date of 26 August 2020, I get a calculated number of days of 44,068!

You're right radzmar, they're both in the same subtree. I think I just found the problem - there was a validation pattern set to the CHI field - when I removed this, it works! But now the user can enter the wrong number of digits. I do need a validation pattern to make sure that the user enters exac...

https://imgur.com/gallery/UU44AM2

kprokopi - well observed; somehow I had placed it under "calculate" - I changed it to "exit*" - though unfortunately it still doesn't work. You say that "the script must be in the date input field" - I presume you mean the numeric field? The 10-digit number is being entered into a numeric field. Tha...

It's set to JavaScript, and I'm pretty sure I have the correct SOM expression - but it's still not working. Do I need to set any particular settings in the numeric field's field or value settings?

Thanks radzmar. I replaced "Textfield1" with "form1.Page1subform.PatientSubform.AgeCalculated" in your script, but no age is outputted. Just to confirm, the first field is a numeric field, and the output field is a text field with value type "user entered - optional"?

Thanks radzmar. I selected the numeric field, and pasted the code above into the script editor ("show" says "calculate"). Do I need to change "Textfield1" in your script to the name of the field that will contain the age? If so, do I just put the name of the field, or do I have to enter all the subf...