My current app is .NET web based app. It is used by client to follow up on employees work time attendance. Both managers and employees manage their time attendance by accessing the web. Managers get reports about all employees in their department, while each employee can get report for his own attendance. We use MSSQL DB.
Managers can Approve or reject requests for leave or overtime work. Employees can request Off work time from direct manager. Human resources approve vacation requests too. Work hours sheet is uploaded to HR automatically at last day of month.