temporalio/temporal · warning

%s has invalid Step

Error message

%s has invalid Step

What it means

After parsing the step value following a '/', makeRange requires the step to be a positive integer (>= 1). A zero or negative step (e.g. "*/0" or "1-5/-2") yields this error naming the field, since a non-positive step would produce an empty or infinite range.

Source

Thrown at service/worker/scheduler/calendar.go:442

		if slashes > 1 {
			// Inputs like "3/5/7" should yield the canonical "too many slashes" error
			// (instead of a later strconv parse error) so tests get consistent results.
			return nil, fmt.Errorf("%s has too many slashes", field)
		}
		if slashes == 1 {
			// A single slash introduces an integer step.
			skipParts := strings.SplitN(part, "/", 2)
			// Count==1 guarantees len==2; only need to ensure the right side is non-empty.
			if skipParts[1] == "" { // e.g. "5/"
				return nil, fmt.Errorf("%s missing step value", field)
			}
			part = skipParts[0]
			step, err = strconv.Atoi(skipParts[1])
			if err != nil {
				return nil, err
			}
			if step < 1 {
				return nil, fmt.Errorf("%s has invalid Step", field)
			}
			hasStep = true
		}

		start, end := minVal, maxVal
		if part != "*" {
			if strings.Contains(part, "-") {
				// Only a single dash is allowed to denote a range (e.g. "1-5").
				// Inputs with multiple dashes like "1-5-7" should raise the
				// canonical "too many dashes" error expected by tests.
				if strings.Count(part, "-") > 1 { // no negative numbers are expected in spec
					return nil, fmt.Errorf("%s has too many dashes", field)
				}
				rangeParts := strings.SplitN(part, "-", 2)
				if len(rangeParts) != 2 {
					return nil, fmt.Errorf("%s has too many dashes", field)
				}
				if start, err = parseValue(rangeParts[0], minVal, maxVal, parseMode); err != nil {

View on GitHub (pinned to bde624efd1)

Solutions

1. Use a step >= 1, e.g. "*/0" → "*/1" or "*/5".
2. Clamp computed interval values to a minimum of 1 before rendering the spec.
3. Validate spec inputs at the application boundary before creating the schedule.
4. Review which field the error names to pinpoint the bad part.

Example fix

// before
step := intervalSeconds // could be 0
spec := fmt.Sprintf("*/%d", step)
// after
if step < 1 {
    step = 1
}
spec := fmt.Sprintf("*/%d", step)

step, err := strconv.Atoi(stepPart)
if err != nil || step < 1 {
    return errors.New("cron step must be a positive integer")
}

When it happens

Trigger: Submitting a schedule spec field with a step of 0 or negative, like "*/0", "0/0", or "1-5/0"; often the result of arithmetic in generated specs (interval computed as 0).

Common situations: Configuration computed from a duration/interval variable that evaluated to 0; users misremembering cron syntax and using 0 as 'every'; template defaults not initialized.

Related errors

• CronString has time zone but missing fields
• CronString does not have 5-7 fields
• CronString does not have interval after @every
• %s has too many slashes
• %s missing step value

AI-assisted analysis of temporalio/temporal@bde624efd1 (2026-09-01). Data as JSON: /api/errors/e4f48c8bd17940fb. Report an issue: GitHub.