public static RegularTimePeriod createInstance(Class c, Date millisecond, 
                                                   TimeZone zone) {
        RegularTimePeriod result = null;
        try {
            Constructor constructor = c.getDeclaredConstructor(
                    new Class[] {Date.class, TimeZone.class});
            result = (RegularTimePeriod) constructor.newInstance(
                    new Object[] {millisecond, zone});
        }
        catch (Exception e) {
            // do nothing, so null is returned            
        }
        return result;