Step 1: Follow Step 1 to Step 5 in the How to Send SMS above

Step 2: Then click on the Send Later button.

Step 3: In the box that appears below, click to tick Schedule for delivery later

Step 4: In the new box that appears choose the year (in the ignore column), month, day, and time

Step 5: To schedule the message to be sent more than once, click on the Add another schedule date button and also choose the year, month, day, and time

Step 6: Then click on Send SMS