alibaba/spring-cloud-alibaba · error · ParseException

Support for specifying both a day-of-week AND a day-of-month

Error message

Support for specifying both a day-of-week AND a day-of-month parameter is not implemented.

What it means

Thrown at the end of buildExpression when both day-of-month and day-of-week are explicitly specified, or both are '?'. Quartz semantics require exactly one of the two day fields to be constrained and the other to be '?' — you cannot say 'on the 1st AND on Monday' in one expression, nor '?' for both. The check at CronExpression.java:307-309 encodes this mutual exclusion.

Source

Thrown at spring-cloud-alibaba-starters/spring-cloud-starter-alibaba-schedulerx/src/main/java/com/alibaba/cloud/scheduling/schedulerx/util/CronExpression.java:308

			if (exprOn <= DAY_OF_WEEK) {
				throw new ParseException("Unexpected end of expression.",
						expression.length());
			}

			if (exprOn <= YEAR) {
				storeExpressionVals(0, "*", YEAR);
			}

			final TreeSet<Integer> dow = getSet(DAY_OF_WEEK);
			final TreeSet<Integer> dom = getSet(DAY_OF_MONTH);

			// Copying the logic from the UnsupportedOperationException below
			final boolean dayOfMSpec = !dom.contains(NO_SPEC);
			final boolean dayOfWSpec = !dow.contains(NO_SPEC);

			if (!dayOfMSpec || dayOfWSpec) {
				if (!dayOfWSpec || dayOfMSpec) {
					throw new ParseException(
							"Support for specifying both a day-of-week AND a day-of-month parameter is not implemented.", 0);
				}
			}
		}
		catch (final ParseException pe) {
			throw pe;
		}
		catch (final Exception e) {
			throw new ParseException("Illegal cron expression format ("
					+ e.toString() + ")", 0);
		}
	}

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

		int incr = 0;
		int i = skipWhiteSpace(pos, s);

View on GitHub (pinned to 115d590110)

Solutions

Use '?' for the day field you do NOT want to constrain: '0 0 0 1 * ?' (day 1 of month) or '0 0 0 ? * MON' (every Monday).
If you genuinely need both a day-of-month and a day-of-week condition, split into two triggers/jobs.
Ensure you never use '?' for both day fields simultaneously.

Example fix

# before (both day fields specified -> invalid)
0 0 0 1 * MON

# after (constrain only day-of-month, '?' for day-of-week)
0 0 0 1 * ?

Defensive patterns

Strategy: try-catch

Validate before calling

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

Type guard

// quick structural check: exactly one of DOM/DOW should be '?'
static boolean dayFieldsMutuallyExclusive(String[] f) {
    boolean domQ = "?".equals(f[3]);
    boolean dowQ = "?".equals(f[5]);
    return domQ ^ dowQ; // exactly one is '?'
}

Try / catch

try {
    new CronExpression(cron);
} catch (ParseException e) {
    // "Support for specifying both a day-of-week AND a day-of-month parameter is not implemented."
    throw new IllegalArgumentException("Fix cron '" + cron + "': set one day field to '?'", e);
}

Prevention

Quartz rule of thumb: one day field gets a value, the other gets '?'.
Avoid '*' for both day-of-month and day-of-week; replace one with '?'.

When it happens

Trigger: An expression like '0 0 0 1 * 1' (both DOM=1 and DOW=1, neither '?') or '0 0 0 ? * ?' (both '?'). dayOfMSpec/dayOfWSpec are derived from whether the set contains NO_SPEC (the '?' marker).

Common situations: Writing '0 0 0 1 * MON' intending 'the 1st and every Monday'; forgetting to put '?' for the unused day field; pasting a cron that uses '*' for both day fields (common in some cron dialects) instead of '?' for one.

Related errors

AI-assisted analysis of alibaba/spring-cloud-alibaba@115d590110 (2026-08-14). Data as JSON: /api/errors/af0fadb4e13cdc35. Report an issue: GitHub.