Not sure if writing an app for this would be the best solution or not really?  Here's what I need to do.

I need to come up with something to keep track of employee's vactation time.

Basically would need to be able to add users and there total vaction time.  then in a calendar view be able to add vacation time for particular users and have it be able to show me how many day's left that emplyee has total and how many day's used.

Does anyone have anyt thoughts on how to go about this?