Drip

The Drip module will enable a site to deliver periodic messages to users at intervals defined by an administrator. The interval base can be a date supplied by a user, defined by an admin, or based on some other date data, such as a user creation date, or last access date.

The module was originally developed as an appointment reminder for a doctor's office. Subscribers enter a child's birthday and receive reminders to schedule check-up appointments at ages the doctor defines, such as 2 weeks, 6 months, and 3 years, etc.