Fnd_Date_DateAndTimeToISO

            Fnd_Date_DateAndTimeToISO (date{; time}) ➜ Text

              Parameter                 Type               Description
              date                      Date               A date value to convert
              time                      Time               A time value to convert (optional)
              Function result           Text               ISO date formatted as text

            This function returns an ISO 8601 formatted date or date-time value. If only a date is supplied, a calendar
            date is returned in the format YYYY-MM-DD. If both a date and time are supplied, a date-time value is
            returned in the format YYYY-MM-DDThh:mm:ss. If both are passed but the date is !00/00/00! then only
            the time is returned in the format hh:mm:ss.
            For more information, see:
            <http://www.iso.org/iso/en/prods-services/popstds/datesandtime.html>
              $datetimestamp_t:= Fnd_Date_DateAndTimeToISO(today_d;time_h)
              $invoicedate_t:=Fnd_Date_DateToString ([Invoice]InvoiceDate)