There are cases where it is necessary to send sms messages to a single phone number on specific dates and/or repeatedly. Take insurance companies as an example: reminding a single client that their insurance is about to expire by sending a low-cost sms. An auto inspection center that every 2 years needs to remind the client that their vehicle inspection is about to expire - 30 days before, 10 days before. The message could also be non-repetitive.