The Manage Availability tab is to block full days or a specific time range.

HOW TO BLOCK AN ENTIRE DAY?

Step 1:
Click on a date in the calendar.
Step 2:
Select ‘Block Entire Day’ and then Save.

The calendar will update with a strip ‘Limited Availability’ on the backend and on the front-end booking page.
HOW TO RESET?

Step 1:
Click on the date.

Step 2:
Click the reset button. The red strip will dissapear from the backend and front-end.
HOW TO BLOCK A SPECIFIC TIME RANGE?

Click on a date and enter the start and end time for the chosen date.
When done, click the save button.