# Scheduling SMS Messages

With scheduled text messages, you can gain greater control over when your messages will reach your recipients, allowing you to perfectly time promotions, critical alerts, or follow-ups to hit your recipients' phones at the ideal moment.

{% hint style="info" %}
You can schedule messages to be sent up to 20 days (480 hours) in the future. 
{% endhint %}

## Scheduling Messages with the httpSMS API 

When sending messages with the httpSMS API you can use the optional `send_at` parameter to schedule the SMS to be sent at a future time and date. Send the time in the [RFC 3389 format](https://datatracker.ietf.org/doc/html/rfc3339) which also includes the time zone e.g.  `1996-12-19T16:39:57-08:00`

```bash
curl -L \
  --request POST \
  --url 'https://api.httpsms.com/v1/messages/send' \
  --header 'Content-Type: application/json' \
  --header 'x-api-Key: YOUR_API_KEY' \
  --data '{
    "from": "+18005550199",
    "to": "+18005550100",
    "content": "Scheduling a text message in the future",
    "send_at": "2025-12-19T16:39:57-08:00"
  }'
```

## Scheduling bulk messages with Excel

When ending [bulk messages on httpSMS](https://httpsms.com/bulk-messages), you can use the optional `SendTime(optional)` column in the [excel template](https://httpsms.com/templates/httpsms-bulk.xlsx) to set the time when the SMS message will be sent out. \
\
When using excel, set the time in your local time zone in the following format `YYYY-MM-DDTHH:MM:SS` e.g. you can set the time like this `2023-11-13T02:10:01` 

<figure><img src="/files/w7PGiIuwxXMZ5DBcdGct" alt=""><figcaption></figcaption></figure>


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