custom cron interval is not working

Question

I am trying to create custom interval for cron schedule with below code but it is not working,

function cronschedules($schedules) {
$schedules['custom'] = array(
'interval' => 36000, // seconds
   'display'  => __('Custom Interval')
         );
  return $schedules;
 }
add_filter('cron_schedules', 'cronschedules');
wp_schedule_event(time(),'custom','ACPdailyevent');

here is the debug log:

[15-Apr-2014 12:02:12 UTC] PHP Notice:  Undefined index: custom in C:\wamp\www\wp\wp-includes\cron.php on line 111

[15-Apr-2014 12:02:12 UTC] PHP Stack trace:

[15-Apr-2014 12:02:12 UTC] PHP   1. {main}() C:\wamp\www\wp\wp-cron.php:0

[15-Apr-2014 12:02:12 UTC] PHP   2. call_user_func_array() C:\wamp\www\wp\wp-cron.php:87

[15-Apr-2014 12:02:12 UTC] PHP   3. wp_reschedule_event() C:\wamp\www\wp\wp-cron.php:87