alibaba/spring-cloud-alibaba · error · ParseException

Invalid Month value: '{}'

Error message

Invalid Month value: '{}'

What it means

Thrown in storeExpressionVals while parsing the MONTH field: when a token starts with a letter A-Z (so it is treated as a named month), getMonthNumber(sub) returns -1 because the three-letter abbreviation is not recognized (JAN..DEC). The parser then throws ParseException 'Invalid Month value: \'<sub>\''.

Source

Thrown at spring-cloud-alibaba-starters/spring-cloud-starter-alibaba-schedulerx/src/main/java/com/alibaba/cloud/scheduling/schedulerx/util/CronExpression.java:338

	}

	protected int storeExpressionVals(final int pos, final String s, final int type)
			throws ParseException {

		int incr = 0;
		int i = skipWhiteSpace(pos, s);
		if (i >= s.length()) {
			return i;
		}
		char c = s.charAt(i);
		if ((c >= 'A') && (c <= 'Z') && (!s.equals("L")) && (!s.equals("LW")) && (!s.matches("^L-[0-9]*[W]?"))) {
			String sub = s.substring(i, i + 3);
			int sval = -1;
			int eval = -1;
			if (type == MONTH) {
				sval = getMonthNumber(sub) + 1;
				if (sval <= 0) {
					throw new ParseException("Invalid Month value: '" + sub + "'", i);
				}
				if (s.length() > i + 3 && (s.charAt(i + 3) == '-')) {
					i += 4;
					sub = s.substring(i, i + 3);
					eval = getMonthNumber(sub) + 1;
					Assert.isTrue(eval > 0, "Invalid Month value: '" + sub + "'");
				}
			}
			else if (type == DAY_OF_WEEK) {
				sval = getDayOfWeekNumber(sub);
				if (sval < 0) {
					throw new ParseException("Invalid Day-of-Week value: '"
							+ sub + "'", i);
				}
				if (s.length() > i + 3) {
					c = s.charAt(i + 3);
					if (c == '-') {
						i += 4;

View on GitHub (pinned to 115d590110)

Solutions

1. Use a valid three-letter English month abbreviation (JAN,FEB,MAR,APR,MAY,JUN,JUL,AUG,SEP,OCT,NOV,DEC) or a numeric value 1-12.
2. Double-check the spelling; the parser only accepts the exact abbreviations in monthMap.
3. Validate at config load.

Example fix

# before (typo)
0 0 0 * JNA ?

# after
0 0 0 * JAN ?

static String validateCron(String cron) throws ParseException {
    new com.alibaba.cloud.scheduling.schedulerx.util.CronExpression(cron);
    return cron;
}

static final java.util.Set<String> MONTHS = java.util.Set.of(
    "JAN","FEB","MAR","APR","MAY","JUN","JUL","AUG","SEP","OCT","NOV","DEC");
static boolean validMonthToken(String t) {
    return MONTHS.contains(t) || t.matches("\\d+(/\\d+)?(-\\d+)?");
}

try {
    new CronExpression(cron);
} catch (ParseException e) {
    // "Invalid Month value: 'JNA'"
    log.error("Bad month in cron '{}': {}", cron, e.getMessage());
}

When it happens

Trigger: A month field with an unrecognised 3-letter token, e.g. '0 0 0 * ABC ?' or a typo like '0 0 0 * JUN ?' (note: only JAN,FEB,MAR,APR,MAY,JUN,JUL,AUG,SEP,OCT,NOV,DEC are valid — 'ABC' is not). The check at CronExpression.java:343-345 fires when sval <= 0.

Common situations: Typo in a month abbreviation; using a full month name 'JANUARY' instead of 'JAN'; locale/uppercase issues where the value is not uppercased (the parser uppercases the whole expression, so this is usually a genuine typo).

Related errors

• Support for specifying 'L' and 'LW' with other days of the m
• Support for specifying 'L' with other days of the week is no
• Support for specifying multiple "nth" days is not implemente
• Unexpected end of expression.
• Support for specifying both a day-of-week AND a day-of-month

AI-assisted analysis of alibaba/spring-cloud-alibaba@115d590110 (2026-08-14). Data as JSON: /api/errors/4fe908a273c6ebbe. Report an issue: GitHub.