@NonNull
    private static String getBackupDateTime(final Folder backupDir) {
        final long time = getBackupTime(backupDir);
        if (time == NO_ACCESSIBLE_FILE) {
            return StringUtils.EMPTY;
        }
        return Formatter.formatShortDateTime(time);
    }
Private methods containing the real backup process
main/src/main/java/cgeo/geocaching/utils/BackupUtils.java