Mark,
nice block! My students (employes in a nursing home) once a year need to do a specific course and renew their certificate. If not, their license will be expired. I'm looking for an 'alarm system' that gives a sign to the employe to do a specific course before a specific date. Is your block suitable or should I look for another plugin / block?
Important is also that the reminders can be set on an individual base, not on general dates in a course for all enrolled students only. Every employe has got another scheme to renew their certificates...
Last question: is it for 2.x or also for 1.9.x?