I have tried this but an getting an error while parsing additional fields not valid json
def EstimateDeliveryDateField = getFieldByName("Estimate Delivery Date") // Grab the Estimate Delivery Date
def ICAEndDate = getFieldByIName("ICA End Date") //Grab the ICA End Date
double dDays = 7 // Defined number of days
if (ICAEndDateField.value != null) {ICAEndDate.setFormValue(new ate().plus(dDays.toInteger()).format("dd/MMM/yy hh:mm a"))
}