be able to mark tasks/calendar events as non-conflicting

I might not be phrasing this exactly right in the title, but what I mean is that I want to be able to designate a task as something that can happen simultaneously with other things.

For example, part of my morning routine is I sit under a sun lamp and go over my upcoming day. The sun lamp task is half an hour long but I want to be able to schedule things during it without getting the ❗ alert. Or, I have a calendar event for the entirety of my 9-5 workday, and obviously I am doing things during that time, but right now anything I add that takes place between the hours of 9 and 5 on a weekday will trigger the ❗ that it's overlapping tasks.