On Call Schedule

Question

I am trying to create an on call schedule within Adaxes. We have 3 people who rotate through an on call schedule for a week with a backup. I would like to send a text to the primary and a text to the secondary on Monday morning at 9:00am like:

Good morning Bob Jones, you are now on call and John Smith is the backup.

I am fairly new to Adaxes and have tried within Scheduled Tasks with no luck. Below is 3 sample users just to keep things straight:

Users Cell Phone #
1 - Jane Doe 555-456-0123
2 - John Smith 666-789-4567
3 - Bob Jones 777-123-6789

Thanks in advance!