Is there any way to get user registration date and time (like created_at for checkins)?
Maybe there are undocumented feature in https://api.foursquare.com/v2/users/self? Like adding parameter &field=created_at
Tried to get that date from "created_at" parameter of first checkin(or from created_at of "newbie" badge), but many users are checkining first time after months they have registered. So, how to know who is "older"?