hashicorp/nomad · error

invalid start time in schedule: %q; %w

Error message

invalid start time in schedule: %q; %w

What it means

Runtime error in TaskScheduleCron.Next: cronexpr.Parse rejects the cron.start expression (it should already have passed validation, so this indicates an expression that is structurally well-formed but semantically invalid).

Source

Thrown at nomad/structs/task_sched.go:135

func (t TaskScheduleCron) GetTimezone() string {
	if t.Timezone == "" {
		return "Local" // https://pkg.go.dev/time#LoadLocation
	}
	return t.Timezone
}

func (t TaskScheduleCron) Next(from time.Time) (time.Duration, time.Duration, error) {
	// where are we?
	location, err := time.LoadLocation(t.GetTimezone())
	if err != nil {
		return 0, 0, fmt.Errorf("invalid timezone in schedule: %w", err)
	}
	from = from.In(location)

	// values should be pre-validated by this point
	start, err := cronexpr.Parse(t.Start)
	if err != nil {
		return 0, 0, fmt.Errorf("invalid start time in schedule: %q; %w", t.Start, err)
	}
	// get end time for prev to see if we're within the run schedule,
	// and from next to get the next pause time.
	end, err := cronexpr.Parse(t.End + " * * * *") // TODO: if we want to exclude seconds, prefix "* " + t.End here
	if err != nil {
		return 0, 0, fmt.Errorf("invalid end time in schedule: %q; %w", t.End, err)
	}

	startNext := start.Next(from)
	// we'll check the previous start to see if we are currently between it
	// and the previous run's end, i.e. it should be running right now!
	startPrev := start.Next(from.Add(-24 * time.Hour))

	// generate ends from starts, so they always come after
	endNext := end.Next(startNext)
	endPrev := end.Next(startPrev)

	// next end must be on the same day as next start

View on GitHub (pinned to 482b49bf1a)

Solutions

1. Correct the cron.start expression so cronexpr can parse it
2. Verify field ranges (e.g. hours 0-23) match the intended schedule

When it happens

Trigger: Thrown at nomad/structs/task_sched.go:135 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/cbbc6dcae88b0573. Report an issue: GitHub.