I have a vague understanding of how to use Focus. What I want to do is easily turn on Do Not Disturb for a specific period of time. I can turn it on for 1 hour. But before OS15, if I turned it on, it asked if I wanted to turn it on until the end of an appointment that was on my calendar. For instance, I have an appointment for 1 1/2 hours. I would go to Do Not Disturb. It asked if I wanted to turn it on until the end of that appointment. So instead of turning it on for just 1 hour, or until I manually turned it off, it would be on for exactly the duration of the appointment and then I didn't have to remember to turn it back on.