I'd love to be able to specify the time frame for a reminder message to get sent for a patient to book for specific treatments. For example "its been 6 months since your last skin needling session- for best results we want to have this treatment at least every 6 months after your 1st course etc" - whereas other treatments may be every 4 weeks or 3 months. I'd like control over when and who this message is going to- such as those who haven't attended for this particular service in the last 6 months with no future booking for this particular service and able to customize for each particular category or service I provide.