private static SimpleDateFormat createDateFormat() {
        SimpleDateFormat format = new SimpleDateFormat("[dd/MMM/yyyy:HH:mm:ss Z]");
        format.setTimeZone(TimeZone.getTimeZone("UTC"));
        return format;
    }
@author Bjorn Borud
@author Oyvind Bakksjo
container-core/src/main/java/com/yahoo/container/logging/VespaAccessLog.java