---
title: Cron Triggers
description: Run Go tasks on a schedule with Cloudflare Cron Triggers.
---

[Cron Triggers](https://developers.cloudflare.com/workers/configuration/cron-triggers/) invoke your worker on a schedule. The `cloudflare/cron` package runs a Go function for each scheduled event.

## Declare the trigger

```toml
[triggers]
crons = ["* * * * *"]
```

## Schedule a task

`cron.ScheduleTask` registers a `func(ctx context.Context) error` and blocks. Inside the task, `cron.NewEvent(ctx)` returns the cron expression and scheduled time.

```go
func task(ctx context.Context) error {
	e, err := cron.NewEvent(ctx)
	if err != nil {
		return err
	}
	fmt.Println(e.Cron, e.ScheduledTime.Unix())

	// background work that outlives the task
	cloudflare.WaitUntil(func() {
		fmt.Println("Run sub task after returning from main task")
	})
	return nil
}

func main() {
	cron.ScheduleTask(task)
}
```

## Combine with an HTTP server

Use `cron.ScheduleTaskNonBlock` with `workers.ServeNonBlock` to run a cron task and an HTTP server in the same worker — see [Combine multiple triggers](/cloudflare#combine-multiple-triggers). `cron.Done()` closes when the scheduler is done.

## Example projects

- [_examples/cron](https://github.com/syumai/workers-go/tree/main/_examples/cron)
- [_examples/multiple-handlers](https://github.com/syumai/workers-go/tree/main/_examples/multiple-handlers) — HTTP server and cron task together.