created date input field on user/%/edit form - sample code

if you need to have an editable created date field on the user edit form, to be able to change the join date of your users, you can use the following code
this is to be dropped into your custom site module (if you dont have one, you need to create it, see drupal docs on creating modules)

/**
 * Implementation of hook_user().
 */
//* function sitemodule_user
function sitemodule_user($op, &$edit, &$account, $category = NULL) {
        switch ( $op ) {
        case 'form' :
                if ($category != 'account' || !user_access('administer users')) break ;
                $form = array() ;

                $form['sitemodule'] = array(
                        '#type' => 'fieldset' ,
                        '#title' => t('Sitemodule user settings') ,
                        '#description' => t('Custom user settings.') ,
                        '#tree' => TRUE ,
                        '#collapsible' => TRUE ,
                        '#collapsed' => FALSE
                ) ;

                $created = getdate($account->created);
                $form['sitemodule']['_created'] = array(
                        '#type' => 'value' ,
                        '#value' => $account->created
                ) ;
                $form['sitemodule']['created'] = array(
                        '#type' => 'date' ,
                        '#title' => t('User joined date') ,
                        '#description' => t('Set the user created date.') ,
                        '#default_value' => array('year' => $created['year'], 'month' => $created['mon'], 'day' => $created['mday']) ,
                ) ;

                return $form ;
        case 'validate' :
                if ($category != 'account' || !user_access('administer users')) break ;
                $value = $edit['sitemodule']['created'];
                $value_ts = gmmktime(0, 0, 0, $value['month'], $value['day'], $value['year']) + 43200;
                if ($value_ts > time() + 43200) form_set_error('sitemodule', t('Date must be in the past.')) ;
                break ;
        case 'update' :
                if ($category != 'account' || !user_access('administer users')) break ;
                $value = $edit['sitemodule']['created'];
                $edit['sitemodule']['created'] = NULL;
                if ($value == $account->sitemodule['created']) break ;
                $value_ts = gmmktime(0, 0, 0, $value['month'], $value['day'], $value['year']) + 43200;
                db_query("UPDATE {users} SET created = %d WHERE uid = %d", $value_ts, $account->uid);
                break ;
        }
} // function sitemodule_user */

if youre wondering about the gmmktime + 43200 hack, its because i had no idea how drupal manages the timezone on the created users or which functions.. fast hack, please drop a line if you know otherwise
$category != 'account' i think makes sure this is node/%/edit, or should i use arg() better?
i dont need 'insert' handling because i only change the edit 'form', and not the 'register'/admin create one

p.s. im not sure what to set the status of this request to.. or if this is the proper place to contribute this
thanks