You can set reminders when sending an outbound patient message by Engage message daily, weekly or monthly. 

Go to outbound messages and select to either send the message to and individual or multiple patients.

Select 'Set reminder'.

Choose between single or repeat reminders.

If repeat select if you want the reminder to sent  daily, weekly or monthly.

If weekly select the day in the week it will be sent.

Then select the time of day and when you want the reminder to end on or after.