Modifying EOT with hook

Hi,

What I am trying to do is when a member “renews” with the modification form is add +1 year to his expiry date regardless on when he renews. The members ALWAYS expire on April 30th so I simply need to add 1 year to make it April 30th 2014, 2015, etc.

So with the following hooks

add_action('ws_plugin__s2member_during_paypal_notify_during_subscr_modify', 'update_s2_EOT');
add_action('ws_plugin__s2member_during_paypal_notify_during_subscr_signup_w_update_vars', 'update_s2_EOT');

I am doing

function update_s2_EOT($vars = array())
{
    $user_id = $vars['user_id'];

    $existing_eot_time = get_user_field('s2member_auto_eot_time', $user_id);

    $new_eot_time = $existing_eot_time;

    update_user_option ($user_id, 's2member_auto_eot_time', $new_eot_time); 
}

Obviously this isn’t adding 1 year but it’s just an example. I am able to get the user_id but the EOT variable is ALWAYS blank so after the function runs it sets my EOT for the user to empty.

Why is get_user_field(‘s2member_auto_eot_time’, $user_id); returning blank? (I can confirm that $user_id is set).

Thank you