Easy thing, isn't it? Just have to create a database that will have all tasks with relevant information about them and then create a service which will pull them and execute the tasks when needed. Not so hard! As making a wheel :) Just bend a thin wood!
Alternatively you might consider using Windows Task Scheduler.
Bart De Smet wrote an article "Calling the Task Scheduler in Windows Vista (and Windows Server 2008) from managed code"
Hope this helps :)