Timezones are incorrectly saved for Drupal7 [patch attached]

When the new user gets saved to the database, the timezone is saved in a format inconsistent with Drupal 7.

In Drupal 6 the timezone is stored as an offset from GMT in seconds whereas in Drupal 7 the timezone is stored in PHP timezones as detailed here.

It is currently defined as the following:

$user->user_timezone = $user->user_timezone * 60 * 60; # Drupal stores timezones in seconds

In the update from D6 to D7 user_update_7002 is what alters the timezone from an offset to a 'friendly timezone' so perhaps parts of that could be implemented, although that just sets it to NULL.

Another usecase could be to use http://php.net/manual/en/function.timezone-name-from-abbr.php for example:

$second_offset = $user->user_timezone * 60 * 60;
$user->user_timezone = timezone_name_from_abbr("", $second_offset, 0);