Using t() in date_views.inc

There is

  $current = array('' => '<all>', 'now' => t('now'));

in date_views_filters($field) function in date_views.inc.

I think you should use

  $current = array('' => t('<all>'), 'now' => t('now'));

But there is '<All>' option exists already in exposed filter, so it whould be better to use this (IMHO):

  $current = array('' => '', 'now' => t('now'));