protected String addTimestamp(String mangled, long lastModified)
{
if (lastModified != -1) {
StringBuffer buffer = new StringBuffer(mangled.length() + 18);
LocalizationPreferences prefs = _address.getZone().getLocalizationPreferences();
Calendar calendar = Calendar.getInstance(prefs.getTimezoneInstance(), prefs.getLocaleInstance());
calendar.setTime(new Date(lastModified));
buffer.append(mangled);
buffer.append('_');
buffer.append(calendar.get(Calendar.YEAR));
appendWithPrefix(buffer, calendar.get(Calendar.MONTH)+1);