xuxueli/xxl-job · error · ParseException

Increment >= 31 : {}

Error message

Increment >= 31 : {}

What it means

Thrown by checkIncrementRange when a step/increment value in the Day-of-Month field exceeds 31. Since months have at most 31 days, an increment of 32 or more is rejected.

Source

Thrown at xxl-job-admin/src/main/java/com/xxl/job/admin/business/scheduler/cron/CronExpression.java:732

                    i = vs.pos;
                }
                i = checkNext(i, s, val, type);
                return i;
            }
        } else {
            throw new ParseException("Unexpected character: " + c, i);
        }

        return i;
    }

    private void checkIncrementRange(int incr, int type, int idxPos) throws ParseException {
        if (incr > 59 && (type == SECOND || type == MINUTE)) {
            throw new ParseException("Increment >= 60 : " + incr, idxPos);
        } else if (incr > 23 && (type == HOUR)) {
            throw new ParseException("Increment >= 24 : " + incr, idxPos);
        } else if (incr > 31 && (type == DAY_OF_MONTH)) {
            throw new ParseException("Increment >= 31 : " + incr, idxPos);
        } else if (incr > 7 && (type == DAY_OF_WEEK)) {
            throw new ParseException("Increment >= 7 : " + incr, idxPos);
        } else if (incr > 12 && (type == MONTH)) {
            throw new ParseException("Increment >= 12 : " + incr, idxPos);
        }
    }

    protected int checkNext(int pos, String s, int val, int type)
            throws ParseException {

        int end = -1;
        int i = pos;

        if (i >= s.length()) {
            addToSet(val, end, -1, type);
            return i;
        }

View on GitHub (pinned to e74c784f68)

Solutions

1. Reduce the day-of-month increment to 31 or less.
2. For intervals longer than a month, use the month field.
3. Validate step values against 31 for the day-of-month field before building the expression.

Example fix

// before
"0 0 0 1/45 * ?"
// after
"0 0 0 1/15 * ?"

// Validate step increment for day-of-month (field index 3)
String[] parts = cron.trim().split("\\s+");
if (parts.length > 3 && parts[3].contains("/")) {
    int step = Integer.parseInt(parts[3].substring(parts[3].indexOf("/") + 1));
    if (step > 31) throw new IllegalArgumentException("Day-of-month step must be <= 31: " + step);
}

boolean isValidDayOfMonthStep(String domField) {
    if (!domField.contains("/")) return true;
    int step = Integer.parseInt(domField.substring(domField.indexOf("/") + 1));
    return step >= 1 && step <= 31;

try {
    new CronExpression(cron);
} catch (ParseException e) {
    if (e.getMessage().contains("Increment >= 31")) {
        // switch to month-based scheduling
    }
}

When it happens

Trigger: A cron expression like '0 0 0 1/32 * ?' where the increment after '/' in the day-of-month field is >= 32. The check at line 731 tests incr > 31 with type DAY_OF_MONTH.

Common situations: Generating a day-of-month increment dynamically without bounds checking, or confusing the day-of-month maximum with another field's.

Related errors

• Increment >= 60 : {}
• Increment >= 24 : {}
• Increment >= 7 : {}
• Increment >= 12 : {}
• Unexpected character '{}' after '/'

AI-assisted analysis of xuxueli/xxl-job@e74c784f68 (2026-08-14). Data as JSON: /api/errors/0971d06ccf221107. Report an issue: GitHub.