Yes. this is covered in the Acrobat JavaScript API Reference in the util.scand andutil.printd methods.


// custom calculation for the day of week field;
event.value = "";
var cMyDate = this.getField("MyDate").valueAsString;
if(cMyDate != "")
{
var oDate = util.scand("mm/dd/yyyy", cMyDate);
event.value = util.printd("dddd", oDate);
}



Edited by gkaiseril - 11 Jun 2016 at 4:57pm

Yes, it's possible. Use this code as the custom calculation script of the DAY field:

var days = ["SUNDAY", "MONDAY", "TUESDAY", "WEDNESDAY", "THURSDAY", "FRIDAY", "SATURDAY"];
var date = this.getField("DATE").valueAsString;
if (date=="") event.value = "";
else event.value = days[util.scand("dd/mm/yyyy", date).getDay()];