alibaba/spring-cloud-alibaba · error · ParseException

The 'W' option does not make sense with values larger than 3

Error message

The 'W' option does not make sense with values larger than 31 (max number of days in a month)

What it means

Thrown in checkNext when 'W' (nearest weekday) is used in day-of-month but the preceding value exceeds 31 (guard at CronExpression.java:546-547). Since no month has more than 31 days, a 'W' anchor beyond 31 is nonsensical.

Source

Thrown at spring-cloud-alibaba-starters/spring-cloud-starter-alibaba-schedulerx/src/main/java/com/alibaba/cloud/scheduling/schedulerx/util/CronExpression.java:547

			}
			else {
				throw new ParseException("'L' option is not valid here. (pos=" + i + ")", i);
			}
			final TreeSet<Integer> set = getSet(type);
			set.add(val);
			i++;
			return i;
		}

		if (c == 'W') {
			if (type == DAY_OF_MONTH) {
				nearestWeekday = true;
			}
			else {
				throw new ParseException("'W' option is not valid here. (pos=" + i + ")", i);
			}
			if (val > 31) {
				throw new ParseException("The 'W' option does not make sense with values larger than 31 (max number of days in a month)", i);
			}
			final TreeSet<Integer> set = getSet(type);
			set.add(val);
			i++;
			return i;
		}

		if (c == '#') {
			if (type != DAY_OF_WEEK) {
				throw new ParseException("'#' option is not valid here. (pos=" + i + ")", i);
			}
			i++;
			try {
				nthdayOfWeek = Integer.parseInt(s.substring(i));
				if (nthdayOfWeek < 1 || nthdayOfWeek > 5) {
					throw new Exception();
				}
			}

View on GitHub (pinned to 115d590110)

Solutions

1. Use a day value 1-31 before 'W', e.g. '32W' -> '15W'.
2. Range-check any injected day value before building the string.

Example fix

// before
new CronExpression("0 0 0 32W * ?");
// after
new CronExpression("0 0 0 15W * ?"); // nearest weekday to the 15th

// '<n>W' in day-of-month requires n <= 31.
static boolean wAnchorOk(String domField) {
    if (!domField.endsWith("W") || domField.length() < 2) return true;
    try {
        int v = Integer.parseInt(domField.substring(0, domField.length() - 1));
        return v >= 1 && v <= 31;
    } catch (NumberFormatException e) { return false; }
}

try {
    CronExpression cron = new CronExpression(raw);
} catch (ParseException e) {
    throw new IllegalArgumentException("Invalid cron expression: " + raw, e);
}

When it happens

Trigger: `new CronExpression("0 0 0 32W * ?")` (nearest weekday to the 32nd). Any '<n>W' in day-of-month with n > 31.

Common situations: Off-by-one or a value from another field concatenated before 'W'; also a templated day value that is not range-checked.

Related errors

• Increment > 60 : {}
• Increment > 24 : {}
• Increment > 31 : {}
• Increment > 7 : {}
• Increment > 12 : {}

AI-assisted analysis of alibaba/spring-cloud-alibaba@115d590110 (2026-08-14). Data as JSON: /api/errors/80a93196dfe924e6. Report an issue: GitHub.