Okay, I have seen previous questions around this but nothing that has really given an answer around building a Reminder Engine/Service to send out reminders (email or text, this part is abstract) when they come due.

From what I can tell originally in version 7.3 a Reminder engine was provided as an example which has subsequently been removed as the product has evolved/matured.

I am trying to build a service due accomplish this feat.  I have the basic sql to get the simple actvities that are coming due (I have tweaked a bit based on some changes I have made for assigning resources to peeps).  I'll attach that stored procedure, you will notice that I have borrowed your basic stored procedure and just tweaked it for what I need.

What I am struggling with is how do I determine from sql if a recurrence appointment has come due?  Especially, if there is no interaction with the front screen from the end user.  I need to be able to figure out how to translate the next appointment due date straight from the sql database.