An INPUT textfield with custom ID and NAME values

I've tried this and I thought it should work, but in fact - JSCalendar doesn't use this time format I've instructed (from below) and instead it uses the default time format (WITH seconds visible). If I remove ID and NAME parameters, everything works smoothly:

 function startDate() {
   $form['date_field'] = array(
     '#type' => 'textfield',
     '#title' => 'Pick-up date & time',
     '#attributes' => array('class' => 'jscalendar'),
     '#id' => 'date1',
     '#name' => 'edit-date1',
     '#jscalendar_ifFormat' => '%Y-%d-%m %I:%M',
     '#jscalendar_showsTime' => true,
     '#jscalendar_timeFormat' => '12',
  );