diff --git tests/phpunit/tests/query/dateQuery.php tests/phpunit/tests/query/dateQuery.php
index 2f94c4a..735a149 100644
--- tests/phpunit/tests/query/dateQuery.php
+++ tests/phpunit/tests/query/dateQuery.php
@@ -287,6 +287,27 @@ class Tests_Query_DateQuery extends WP_UnitTestCase {
 		$this->assertEquals( $expected_dates, wp_list_pluck( $posts, 'post_date' ) );
 	}
 
+	/**
+	 * @ticket 29908
+	 */
+	public function test_inclusive_before_with_ymd_date() {
+		$p1 = $this->factory->post->create( array(
+			'post_date' => '2008-05-06 13:00:00',
+		) );
+		$p2 = $this->factory->post->create( array(
+			'post_date' => '2008-05-07 13:00:00',
+		) );
+
+		$posts = $this->_get_query_result( array(
+			'date_query' => array(
+				'before' => '2008-05-07',
+				'inclusive' => true
+			),
+		) );
+
+		$this->assertTrue( in_array( $p2, wp_list_pluck( $posts, 'ID' ) ) );
+	}
+
 	public function test_date_query_year_expecting_results() {
 		$posts = $this->_get_query_result( array(
 			'date_query' => array(