[development] module to trigger an action/callback based on a date field ?

Hi Folks I am looking to trigger an event a specified time period before or after the value in a date field. I can't quite believe that there is no existing trigger system for this, but I have not been able to find something. My basic use case is event reminders: 2 weeks before an event, send an email 3 days before, send a reminder 2 days after an event, send a request for feedback I don't see this as complex to build, but I would prefer to build on something shared. Does anyone know of a module to handle this ? Cheers Peter.