How to setup work hours?

This question can mean several things:

How to monitor employees only during their work hours

You can configure when employees are tracked from the Monitoring Settings. Check out this article to learn how: How to change the monitoring schedule?

How to set up work schedule for your employees

You can configure schedules/rota for employees or positions. Check out this article to learn how: How to create/change employee schedule?

How to add, remove or adjust employee work hours

You can add/remove hours from an employee's total time. Check out this article to learn how: How to add / remove time (work hours)?