[user5994461]

The scheduling assistant shows you the timeline hour per hour, with a line for each employee and any meeting they have anywhere. You can even view what any meeting is, if their meetings are not set to private.

I think it's quite good to find a time, with the least conflicts. However given any meeting with more than 3 people in a large organization, it's simply not possible to gather everybody at once, without planning 3 weeks in advance.

one screenshot: https://technology.ku.edu/outlook2013/scheduling-assistant