public static String format(Date date, String dateFormat) {
        if (date == null) {
            return null;
        }
        if (StringUtils.isEmpty(dateFormat)) {
            dateFormat = defaultDateFormat;
        }
        return getCacheDateFormat(dateFormat).format(date);
    }
Format date

@param date
@param dateFormat
@return
fastexcel-core/src/main/java/cn/idev/excel/util/DateUtils.java