I've noted this before, but I'll repeat it here: If the DC meetup could even occasionally occur on a Saturday afternoon instead of a Sunday afternoon, then I would probably attend. But you've coordinated on a time that never works for me. It's probably advantageous to always meet at the same time from the standpoint of consistency of attendance by the same people, but if you want to expand the number of people attending at least irregularly, variability in time would likely work better.