public static Optional<Long> parseWithJavaFormat(final String string, final String format) {
        return convertJavaFormatToJs(format)
                .map(jsFormat -> parseWithJsFormat(string, jsFormat));
    }
Returns the date/time in local time. If the date string has no
timezone information it is assumed to be local time.
See https://momentjs.com/docs/#/parsing/utc/
stroom-core-client-widget/src/main/java/stroom/widget/customdatebox/client/ClientDateUtil.java