Create a campaign and schedule it. Refer here on how to schedule the campaign. 

Navigate -> Marketing -> SMS + -> Action -> Edit

  • Editing the campaign is used for the scheduled campaigns. 
  • When clicked on the edit action from the list of campaigns, the edition of all the data (from Campaign Info to Delivery) in the campaign will be processed.
  •  You will be re-directed to the edit campaign page from there you will be able to edit before the campaign scheduled time.  

Explanation Video