If you are looking to manage when employees can take time off, say 2 weeks from now or further out, read more here on how to do it.
What are user defined fields and how do I use them?
TimeWellScheduled allows you to manage the OT rules at a global level, as well at the employee level. Read here on how to manage it.
Sometimes you need to create a shift but not sure who to assign it too you want to let your employees take it on their own To do this, use the OPEN SHIFT module. Read more here.