Web service for tracking employees' working time and reporting

Web service for a company with more than 100 employees.
Functionality:
1. Creating work schedules
2. Creating vacations
3. Tracking worked hours
4. Tracking vacations for the current + previous years
5. Access levels for department managers and administrators
6. Ability to select the reason for absence or overtime
7. Ability to add comments about an employee's work on each of their working days
8. Generating reports in PDF format for the selected period