Time sheet and Attendance Management system

We are looking to develop a web based time sheet cum attendance management system for our company. The details of the requirements are as given below: Employee Login: Each employee will have a login id and Password in the application. When an employee login, they will see a calendar for the month with provision to add number of hours worked. Employees can fill in these details either every day or once in a month. Options to Mark Holidays, Leaves etc. At the end of the month employees should have an option to submit the time sheet to their Manager for approval. Provision to include Managers email ids. On submission, the calendar will be converted to an excel time sheet and will be send to the email ids provided for approval. The details entered into time sheet will be taken as attendance of the employee for the month by the system. Attendance system should have to show leave eligibility, leaves taken and leave balance. Also total number of days present in a month. Provision to generate some simple reports on attendance ( can be discussed).