In an effort to de-clutter the Wikimedia NYC calendar -- and to support the various initiatives and enhance event calendaring within Wikimedia -- after some active discussion, Wikimedia NYC (well that would be me) has set up the following calendars.
Ideally a calendar solution would be open source and Wiki-friendly (see https://phabricator.wikimedia.org/T1035 Consolidate the many tech events calendars in Phabricator's calendar), but Google calendars seem to provide the most functionality right now so this is seen as an interim solution. For reference: https://phabricator.wikimedia.org/calendar/