In order to send a delayed message, i.e. distribute it at a future time or date go to the SMS Sending Screen and follow the following steps:
a) Insert all the message information as do when you send an regular / immediate message (message text, recipients, optout option, etc.).
b) Select the Delayed radio button under Additional options – Delivery time.
c) Set the time and date at which you want your message to actually be sent:
d) Once done and all is properly configured press on the Send SMS blue button at the bottom of the screen. The message will be queued for distribution at the time and date you selected.
Meanwhile at any time before it is actually sent, if you wish to cancel the sending or change the message wording you can always go to the Future Messages Report to edit your delayed message: