users

There is no accurate registration date information for the first couple years, the first couple thousand users, of Drupal.org's history. There is even a discrepancy between the posted "Member for" dates and the apparent launch of the site.

Between users http://drupal.org/user/2119 and http://drupal.org/user/2120 the date of registration (time on site, or "Member for") jumps by two years and two weeks.

Run trac-admin commands on the server hosting the trac sites. In our Debian server setup at least, individual projects are in the /srv/trac/ directory, and every trac-admin command should be followed by the path to the project you care about.

For more information than man will give you, use:

trac-admin help

To make a user an admin (I believe this will automatically create a new user if it has to) --

trac-admin /srv/trac/example permission add username TRAC_ADMIN