I want to write a scheduling application. Basically people are going to submit schedules like "every thursday from 3-4" or "mon, wed, fri, 10-11" or something like that. I want to display the schedule on a calendar, allow people to edit the schedule or just one instance, compare the actual times worked to scheduled times (late, early etc).
I know somebody has already done this before so before starting I thought I would ask if anybody knows a project with a liberal enough license for me to plunder :).
Since I need to include this in an existing project I just want to take a look at how they stored the schedule, how they displayed it, how and when they materialized the events, etc. I don't want to take the application as a whole and modify it.
Failing that does anybody have a link to some sort of a document which details best practices when it comes to scheduling?
TIA.