Adding automatic date to PDF that autofills when form is manipulated

[wcervera]

My client needs a PDF to update the date only if the PDF form is manipulated. If a viewer simply opens the form and and doesnt manipulate any fields, then the date would not change. But if they fill out the form in any way, then the date when update automatically and be locked so user cannot backfill the date.

I have found posts about having a PDF automatically update the date when opened, but this is not what I need. 

[try67]

Use this code in the field's custom Calculation script:

event.value = util.printd("mm/dd/yyyy", new Date());