public JQueryDateTimePatternBuilder appendDayNameShort() {
        sb.append("D");
        return this;
    }
Builder for the pattern format as defined by the jquery UI datepicker, see
https://api.jqueryui.com/datepicker; and the jquery timepicker, see
http://trentrichardson.com/examples/timepicker. Wraps a {@link StringBuilder}
and provides additional convenience methods. If necessary, you can also
access the raw {@link #getStringBuilder()}.
primefaces/src/main/java/org/primefaces/convert/JQueryDateTimePatternBuilder.java