private static void visitMonthToken(int repetitions, JQueryDateTimePatternBuilder builder) {
        // M and MM is a numeric month
        // MMM and MMMM are month names
        switch (repetitions) {
            case 1:
                builder.appendMonthOfYearNoLeadingZeros();
                break;
            case 2:
                builder.appendMonthOfYearWithLeadingZeros();
                break;
            case 3:
                builder.appendMonthNameShort();
                break;
            default: // 4+
                builder.appendMonthNameLong();
                break;
        }
    }
Month token 'M', 'MM', 'MMM', 'MMMM'.
<ul>
<li>M is a numeric month without leading zeros</li>
<li>MM is a numeric month with leading zeros</li>
<li>MMM is a short month name</li>
<li>MMMM is a long month name</li>
</ul>
More than four 'M' are treated as 'MMMM'.
primefaces/src/main/java/org/primefaces/convert/CombinedDateTimePatternTokenVisitor.java