diff --git a/src/wp-includes/date.php b/src/wp-includes/date.php
index 58071d3d3a..a35fada6d1 100644
--- a/src/wp-includes/date.php
+++ b/src/wp-includes/date.php
@@ -368,7 +368,7 @@ class WP_Date_Query {
 
 		// Hours per day.
 		$min_max_checks['hour'] = array(
-			'min' => 1,
+			'min' => 0,
 			'max' => 23
 		);
 
@@ -394,7 +394,7 @@ class WP_Date_Query {
 			foreach ( (array) $date_query[ $key ] as $_value ) {
 				$is_between = $_value >= $check['min'] && $_value <= $check['max'];
 
-				if ( ! $is_between ) {
+				if ( ! is_numeric( $_value ) || ! $is_between ) {
 					$error = sprintf(
 						/* translators: Date query invalid date message: 1: invalid value, 2: type of value, 3: minimum valid value, 4: maximum valid value */
 						__( 'Invalid value %1$s for %2$s. Expected value should be between %3$s and %4$s.' ),
diff --git a/tests/phpunit/tests/date/query.php b/tests/phpunit/tests/date/query.php
index 2169d88efb..72c7d73f41 100644
--- a/tests/phpunit/tests/date/query.php
+++ b/tests/phpunit/tests/date/query.php
@@ -857,13 +857,13 @@ class Tests_WP_Date_Query extends WP_UnitTestCase {
 	 */
 	public function test_validate_date_values_hour() {
 		// Valid values.
-		$hours = range( 1, 23 );
+		$hours = range( 0, 23 );
 		foreach ( $hours as $hour ) {
 			$this->assertTrue( $this->q->validate_date_values( array( 'hour' => $hour ) ) );
 		}
 
 		// Invalid values.
-		$hours = array( -1, 24, 25, 'string who wants to be a int' );
+		$hours = array( -1, 24, 25, 'string' );
 		foreach ( $hours as $hour ) {
 			$this->assertFalse( $this->q->validate_date_values( array( 'hour' => $hour ) ) );
 		}