To schedule a message, you will need to begin composing a message.
Once you have composed your message,
to schedule a message, rather than using the send button use the "schedule" button instead. Set the date and time you wish the message to be sent and then click "schedule message".
To view any scheduled messages, click either "view upcoming scheduled message" or open up the menu and then "Message scheduling".
The message scheduling will then show you all messages scheduled for teams you are able to view.
This shows you the details of when the message is due to send, who scheduled it and how many accounts will tweet it. You can view more specific details by clicking "view".
From here, you can see the content of the message, again when it is due to send, who has scheduled it, the date the message was composed and also which social media accounts will be sending the message out.