private void setTimeZone(final FormatOptions.Builder builder) {
        final String timeZone = ClientTimeZone.getTimeZone();
        if (timeZone != null) {
            builder.timeZone(timeZone);
        }
    }
Shifts the currently specified date by the given number of months. The day
of the month will be pinned to the original value as far as possible.

@param deltaMonths - number of months to be added to the current date
stroom-core-client-widget/src/main/java/stroom/widget/datepicker/client/DateTimeModel.java