Web-based Attendance and Payroll System -- 2

I'm seeking a developer to create a web-based attendance and payroll system.

Core functionalities needed:
- Employee clock-in/out
- Payroll calculation
- Leave management

Basic user authentication is required, but only at a basic level.

Ideal skills and experience:
- Experience in developing web-based applications
- Strong understanding of payroll and attendance systems
- Ability to implement user authentication

Please provide samples of similar work done and an estimated timeline for completion.