There are processes and procedures that outline what steps are to be taken and when they should be taken with regards to the start (or end) of the process. Examples vary from taking vitamin pills (please see http://calde.co/5cyppg9) for 10 days to following a diet plan to legal procedures and applications.
Caldeco (http://calde.co) offers a simple way to capture processes' structures and instantiate them when necessary. With calendar templates it is possible to create events positioned relative to the template start (or end) point, e.g. "Take first vitamin pill 12 hours after start", "Send document set A 30 days after initial application", etc.
To instantiate a calendar template user provides start date (or end date), after instantiation calendar template becomes a regular calendar (in iCalendar format) that can be added to a user's calendaring solution of choice, events along with reminders.