To set office hours in 3CX Version 20, you'll typically follow these steps:

1. Log in to your 3CX Management Console: Open your web browser and navigate to the URL of your 3CX Management Console. Log in with your administrator credentials.

2. Click on Admin.

3. Click on Office Hours: Click on this to access the configuration for your office hours.

4. Set Your Time Zone: Ensure that your time zone is correctly configured to reflect your location.

5. Define Office Hours: Look for the section where you can set your office hours. Typically, you'll have options to specify the start and end times for each day of the week. Some systems might also allow you to define different hours for holidays or special occasions.

6. Save Your Changes: After you've configured your office hours to your liking, remember to save your changes.

7. Test Your Configuration: It's always a good idea to test your configuration to ensure that calls are routed correctly based on your office hours.