# Delay

When publishing a message, you can delay it for a certain amount of time before
it will be delivered to your API. See the [pricing table](https://upstash.com/pricing/qstash) for more information

<Warning>
For free: The maximum allowed delay is  **7 days**.

For pay-as-you-go: The maximum allowed delay is  **1 year**.

For fixed pricing: The maximum allowed delay is  **Custom(you may delay as much as needed)**.
</Warning>

## Relative Delay

Delay a message by a certain amount of time relative to the time the message was
published.

The format for the duration is `<number><unit>`. Here are some examples:

- `10s` = 10 seconds
- `1m` = 1 minute
- `30m` = half an hour
- `2h` = 2 hours
- `7d` = 7 days

You can send this duration inside the `Upstash-Delay` header.

<CodeGroup>
```shell cURL
curl -XPOST \
    -H 'Authorization: Bearer XXX' \
    -H "Content-type: application/json" \
    -H "Upstash-Delay: 1m" \
    -d '{ "hello": "world" }' \
    'https://qstash.upstash.io/v2/publish/https://my-api...'
```

```typescript Typescript
import { Client } from "@upstash/qstash";

const client = new Client({ token: "<QSTASH_TOKEN>" });
const res = await client.publishJSON({
  url: "https://my-api...",
  body: { hello: "world" },
  delay: 60,
});
```

```python Python
from qstash import QStash

client = QStash("<QSTASH_TOKEN>")
client.message.publish_json(
    url="https://my-api...",
    body={
        "hello": "world",
    },
    headers={
        "test-header": "test-value",
    },
    delay="60s",
)
```
</CodeGroup>

<Warning>

`Upstash-Delay` will get overridden by `Upstash-Not-Before` header when both are
used together.

</Warning>

## Absolute Delay

Delay a message until a certain time in the future. The format is a unix
timestamp in seconds, based on the UTC timezone.

You can send the timestamp inside the `Upstash-Not-Before` header.

<CodeGroup>
```shell cURL
curl -XPOST \
    -H 'Authorization: Bearer XXX' \
    -H "Content-type: application/json" \
    -H "Upstash-Not-Before: 1657104947" \
    -d '{ "hello": "world" }' \
    'https://qstash.upstash.io/v2/publish/https://my-api...'
```

```typescript Typescript
import { Client } from "@upstash/qstash";

const client = new Client({ token: "<QSTASH_TOKEN>" });
const res = await client.publishJSON({
  url: "https://my-api...",
  body: { hello: "world" },
  notBefore: 1657104947,
});
```

```python Python
from qstash import QStash

client = QStash("<QSTASH_TOKEN>")
client.message.publish_json(
    url="https://my-api...",
    body={
        "hello": "world",
    },
    headers={
        "test-header": "test-value",
    },
    not_before=1657104947,
)
```
</CodeGroup>

<Info>

`Upstash-Not-Before` will override the `Upstash-Delay` header when both are used
together.

</Info>

## Delays in Schedules

Adding a delay in schedules is only possible via `Upstash-Delay`. The
delay will affect the messages that will be created by the schedule and not the
schedule itself.

For example when you create a new schedule with a delay of `30s`, the messages
will be created when the schedule triggers but only delivered after 30 seconds.