code: public String getAsShortText(int fieldValue, Locale locale) {
          return GJLocaleSymbols.forLocale(locale).dayOfWeekValueToShortText(fieldValue);
      }
docs: Get the abbreviated textual value of the specified time instant.
  
  @param fieldValue  the field value to query
  @param locale  the locale to use
  @return the day of the week, such as 'Mon'