Here's an example of how it works:
You set a 3 hour focus time block each day. 3 hours of focus time block events will be added to your calendar.
As tasks get scheduled, they will replace the focus time blocks. For example, if you have 1 hour of tasks scheduled, the 3 hour focus time block will be reduced to 2 hours.
How to set up focus time:
Go to settings on your computer.
Click "Focus time" on the left.
Enable focus time.
Choose the days/times you'd like to have focus time.