# 35117: Scheduling does not support this timestamp

Log Type: APPLICATION

Log Level: ERROR

## Description

This error occurs when you create a scheduled message with a `SendAt` value outside the supported scheduling window. Set `SendAt` in ISO 8601 format and choose a time between 15 minutes and 35 days in the future.

### Possible causes

* `SendAt` is less than 15 minutes from the time Twilio receives the `POST` request.
* `SendAt` is more than 35 days in the future.
* Your application scheduled the message too close to the minimum window, so processing time caused the request to arrive after the requested time fell inside the 15-minute limit.

### Possible solutions

* Update `SendAt` so the scheduled time is at least 15 minutes ahead and no more than 35 days ahead when Twilio receives the request.
* Format `SendAt` as an ISO 8601 timestamp, for example `2021-11-30T20:36:27Z`.
* If you schedule messages near the minimum window, add a small buffer so request and network processing time do not push the timestamp out of range.

#### Additional resources

* [Message Scheduling](/docs/messaging/features/message-scheduling)
* [Message Resource](/docs/messaging/api/message-resource)
* [Messaging Services](/docs/messaging/services)