public String format(Calendar calendar) {
        return format(calendar, new StringBuffer(mMaxLengthEstimate))
            .toString();
    }
@param pattern {@link java.text.SimpleDateFormat} compatible pattern
@param timeZone optional time zone, overrides time zone of formatted
date
@param locale optional locale, overrides system locale
@param symbols optional date format symbols, overrides symbols for
provided locale
xmppserver/src/main/java/org/jivesoftware/util/FastDateFormat.java