$date_query = array(
    'column' => 'post_date',
    'relation' => 'OR',

    // After 2 PM
    array(
        'hour' => 14,
        'compare' => '>',
    ),

    // Before 11:43:23 AM
    array(
        'hour' => 11,
        'minute' => 43,
        'second' => 23,
        'compare' => '<',
    ),

    array(
        'inclusive' => true,
        'after' => '2010-09',
        'before' => array(
            'year' => 2011,
            'month' => 9,
            'day' => 10,
            'hour' => 16,
            'minute' => 25,
            'second' => 32,
        )
    ),
    array(
        'before' => array(
            'year' => 2002,
        ),
    ),
);

/*

( DATE_FORMAT( post_date, '%H' ) > 14.000000 ) OR ( DATE_FORMAT( post_date, '%H.%i%s' ) < 11.432300 ) OR ( post_date >= '2010-09-01 00:00:00' AND post_date <= '2011-09-10 16:25:32' ) OR ( post_date < '2002-01-01 00:00:00' )

*/