---
title: 'Schedule'
description: 'Fires the workflow on a recurring cron schedule.'
---
# Schedule

Runs the workflow every time the cron expression matches. OneHazel evaluates
schedules once per minute via a `pg_cron` job, so the minimum granularity is
one minute.

## When to use

- Hourly/daily/weekly rollups.
- Periodic health pings to external services.
- Batch reconciliation that doesn't need real-time events.
- Anything you'd historically put in a cron tab.

## Configuration

| Field | Required | What it does |
|---|---|---|
| `cronExpression` | Yes | Five-field cron: `minute hour day month weekday`. Seconds and year are not supported. |
| `timezone` | No | Which timezone to evaluate the cron in. Defaults to UTC. |

## Cron cheat sheet

| Expression | Runs |
|---|---|
| `* * * * *` | Every minute |
| `0 * * * *` | Top of every hour |
| `0 9 * * *` | 9:00 AM daily |
| `0 0 * * 0` | Midnight every Sunday |
| `*/15 * * * *` | Every 15 minutes |
| `0 9 * * 1-5` | 9:00 AM weekdays only |
| `0 0 1 * *` | Midnight on the 1st of each month |

The timezone setting affects when the cron fires, not the events themselves.
Pick the timezone your business operates in so "9 AM daily" makes sense to
humans.

## What it outputs

The trigger produces a payload containing the scheduled tick time:

```
{
  trigger: {
    data: {
      scheduledAt: "2026-04-18T09:00:00.000Z",
      cron: "0 9 * * *"
    }
  }
}
```

Downstream nodes can reference `{{trigger.data.scheduledAt}}` if they need
the exact tick time (useful for reports and audit logs).

## Gotchas

- **Clock drift**: the scheduler ticks every ~60 seconds, so expect ±1
  minute of jitter on fire times. Don't rely on exact-to-the-second timing.
- **Missed ticks**: if the scheduler is down when your cron fires, the tick
  is missed — OneHazel does **not** replay missed schedules.
- **Overlapping runs**: if your workflow takes longer than one minute to
  finish and your cron fires every minute, you will have overlapping
  executions. Wrap long-running work in idempotency guards if this matters.