flowable/flowable-engine · error · ParseException

Support for specifying 'L' with other days of the week is no

Error message

Support for specifying 'L' with other days of the week is not implemented

What it means

The same guard as the day-of-month 'L' check, applied to the day-of-week field: an expression like 'MON,L' (length > 1, contains 'L' and a comma) is rejected because 'L' in day-of-week (last day of week, or nL) combined with other listed days is not implemented. Thrown as ParseException from buildExpression.

Source

Thrown at modules/flowable-engine-common/src/main/java/org/flowable/common/engine/impl/calendar/CronExpression.java:498

            if (years == null) {
                years = new TreeSet<>();
            }

            int exprOn = SECOND;

            StringTokenizer exprsTok = new StringTokenizer(expression, " \t", false);

            while (exprsTok.hasMoreTokens() && exprOn <= YEAR) {
                String expr = exprsTok.nextToken().trim();

                // throw an exception if L is used with other days of the month
                if (exprOn == DAY_OF_MONTH && expr.indexOf('L') != -1 && expr.length() > 1 && expr.contains(",")) {
                    throw new ParseException(
                            "Support for specifying 'L' and 'LW' with other days of the month is not implemented", -1);
                }
                // throw an exception if L is used with other days of the week
                if (exprOn == DAY_OF_WEEK && expr.indexOf('L') != -1 && expr.length() > 1 && expr.contains(",")) {
                    throw new ParseException(
                            "Support for specifying 'L' with other days of the week is not implemented", -1);
                }
                if (exprOn == DAY_OF_WEEK && expr.indexOf('#') != -1
                        && expr.indexOf('#', expr.indexOf('#') + 1) != -1) {
                    throw new ParseException("Support for specifying multiple \"nth\" days is not implemented.", -1);
                }

                StringTokenizer vTok = new StringTokenizer(expr, ",");
                while (vTok.hasMoreTokens()) {
                    String v = vTok.nextToken();
                    storeExpressionVals(0, v, exprOn);
                }

                exprOn++;
            }

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

View on GitHub (pinned to d6d39ce1c6)

Solutions

1. Remove 'L' from the day-of-week list; list only concrete day names/numbers
2. Use a dedicated expression like '0 0 12 ? * FRI' for the last-weekday need and a second schedule for extra days
3. Use the 'nL' form (e.g. '6L' = last Friday) alone in the field if that matches the intent

Example fix

// before
String cron = "0 0 12 ? * MON,FRI,L"; // unsupported
// after
String cron = "0 0 12 ? * MON,FRI"; // schedule the 'L' case with a second timer '0 0 12 ? * SAT' if needed

String dow = fields[5];
if (dow.indexOf('L') != -1 && dow.contains(",")) throw new IllegalArgumentException("L cannot be combined in a day-of-week list");

try { new CronExpression(expr, clockReader); }
catch (ParseException e) { if (e.getMessage().contains("'L' with other days")) { /* fix day-of-week field */ } throw e; }

When it happens

Trigger: new CronExpression(expr, clockReader) where the 6th field (day-of-week) contains 'L' plus a comma, e.g. '0 0 12 ? * FRI,L'.

Common situations: Attempting 'last Friday plus other days' in one cron field; expression ported from a cron implementation with richer 'L' support; typo leaving a stray 'L' inside a day list.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• Support for specifying 'L' and 'LW' with other days of the m
• 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
• Failed to parse scheduler expression:

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/2c9f832fa1975428. Report an issue: GitHub.