> ## Documentation Index
> Fetch the complete documentation index at: https://confect.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Cron Jobs

> Schedule recurring tasks with cron jobs.

Define cron jobs in `confect/crons.ts` using `CronJob` and `CronJobs` from `@confect/server`. Each job has a unique identifier, a schedule, and a ref to an internal mutation or action.

Schedules are either an Effect [`Cron`](https://effect.website/docs/scheduling/cron) (cron expression) or a [`Duration`](https://effect.website/docs/data-types/duration/) (fixed interval). The Confect CLI re-exports the result into `convex/crons.ts`.

<Note>
  `Cron` schedules must not use a custom `seconds` field—Convex cron expressions
  only support minute-level granularity. For sub-minute scheduling, use a
  `Duration` interval instead.
</Note>

<Note>
  `Duration` intervals must be a positive, whole number of seconds, minutes, or
  hours. Sub-second durations (e.g. `Duration.millis(500)`) are not supported.
</Note>

```ts confect/crons.ts theme={null}
import * as Cron from "effect/Cron";
import * as Duration from "effect/Duration";
import { CronJob, CronJobs } from "@confect/server";
import refs from "./_generated/refs";

export default CronJobs.make()
  .add(
    CronJob.make(
      "clear stale sessions",
      Cron.make({
        minutes: [0],
        hours: [],
        days: [],
        months: [],
        weekdays: [],
      }),
      refs.internal.sessions.clearStale,
    ),
  )
  .add(
    CronJob.make(
      "send weekly digest",
      Cron.unsafeParse("0 9 * * 1"),
      refs.internal.emails.sendDigest,
    ),
  )
  .add(
    CronJob.make(
      "send hourly reminder",
      Duration.hours(1),
      refs.internal.notifications.sendReminder,
    ),
  )
  .add(
    CronJob.make(
      "payment reminder",
      Cron.unsafeParse("0 16 1 * *"),
      refs.internal.payments.sendPaymentEmail,
      { email: "billing@example.com" },
    ),
  );
```

`CronJob.make` accepts a unique identifier, a schedule (`Cron` or `Duration`), a ref to an internal mutation or action, and an optional args object matching the ref's args schema. `CronJobs.make()` creates an empty collection; each `.add()` call returns a new `CronJobs` object, so calls can be chained.

For the full scheduling APIs, see the [Effect `Cron` documentation](https://effect.website/docs/scheduling/cron), the [Effect `Duration` documentation](https://effect.website/docs/data-types/duration/), and the [Convex cron jobs documentation](https://docs.convex.dev/scheduling/cron-jobs).