35117: Scheduling does not support this timestamp

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.

• 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.

• 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.

• Message Scheduling
• Message Resource
• Messaging Services