---
type: docs
title: "Cron binding spec"
linkTitle: "Cron"
description: "Detailed documentation on the cron binding component"
aliases:
  - "/operations/components/setup-bindings/supported-bindings/cron/"
---

## Component format

To setup cron binding create a component of type `bindings.cron`. See [this guide]({{< ref "howto-bindings.md#1-create-a-binding" >}}) on how to create and apply a binding configuration.


```yaml
apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: <NAME>
  namespace: <NAMESPACE>
spec:
  type: bindings.cron
  version: v1
  metadata:
  - name: schedule
    value: "@every 15m" # valid cron schedule
```

## Spec metadata fields

| Field              | Required | Binding support |  Details | Example |
|--------------------|:--------:|-------|--------|---------|
| schedule | Y | Input/Output |  The valid cron schedule to use. See [this](#schedule-format) for more details | `"@every 15m"`

### Schedule Format

The Dapr cron binding supports following formats:

| Character |	Descriptor        | Acceptable values                             |
|:---------:|-------------------|-----------------------------------------------|
| 1	        | Second	          | 0 to 59, or *                                 |
| 2	        | Minute	          | 0 to 59, or *                                 |
| 3	        | Hour	            | 0 to 23, or * (UTC)                           |
| 4	        | Day of the month	| 1 to 31, or *                                 |
| 5	        | Month	            | 1 to 12, or *                                 |
| 6	        | Day of the week	  | 0 to 7 (where 0 and 7 represent Sunday), or * |

For example:

* `30 * * * * *` - every 30 seconds
* `0 15 * * * *` - every 15 minutes
* `0 30 3-6,20-23 * * *` - every hour on the half hour in the range 3-6am, 8-11pm
* `CRON_TZ=America/New_York 0 30 04 * * *` - every day at 4:30am New York time

> You can learn more about cron and the supported formats [here](https://en.wikipedia.org/wiki/Cron)

For ease of use, the Dapr cron binding also supports few shortcuts:

* `@every 15s` where `s` is seconds, `m` minutes, and `h` hours
* `@daily` or `@hourly` which runs at that period from the time the binding is initialized

## Listen to the cron binding

After setting up the cron binding, all we need to do is listen on an endpoint that matches the name of our component. let's assume the <NAME> is `scheduled`. Note that this will be made as a HTTP `POST` request. The example below shows how a simple Node.js Express application can receive calls on the `/scheduled` endpoint and write a message to the console.
  
```js
app.post('/scheduled', async function(req, res){
    console.log("scheduled endpoint called", req.body)
    res.status(200).send()
});
```
  
If we run this, we'll see that the /scheduled endpoint is called every five minutes by the Dapr sidecar.


## Binding support

This component supports both **input and output** binding interfaces.

This component supports **output binding** with the following operations:

- `delete`

## Related links

- [Basic schema for a Dapr component]({{< ref component-schema >}})
- [Bindings building block]({{< ref bindings >}})
- [How-To: Trigger application with input binding]({{< ref howto-triggers.md >}})
- [How-To: Use bindings to interface with external resources]({{< ref howto-bindings.md >}})
- [Bindings API reference]({{< ref bindings_api.md >}})
- [Scheduled tasks with the Cron binding in Dapr](https://markheath.net/post/dapr-cron-binding)