This will be at the food court at the Newgate Mall from noon to 1:00 pm. I expect that people will remain and talk for as long as they want. The goal is to meet right under the skylight, but the muggles may not cooperate. Just look for the group of people trying to look inconspicuous, but failing.
The meeting is in the food court at lunch time. You may take advantage of the time and place, but no purchase is expected or required.