diff --git a/core/lib/Drupal/Core/Datetime/Element/Datelist.php b/core/lib/Drupal/Core/Datetime/Element/Datelist.php
index b560065..c68a787 100644
--- a/core/lib/Drupal/Core/Datetime/Element/Datelist.php
+++ b/core/lib/Drupal/Core/Datetime/Element/Datelist.php
@@ -55,7 +55,7 @@ public static function valueCallback(&$element, $input, FormStateInterface $form
     $date = NULL;
     if ($input !== FALSE) {
       $return = $input;
-      if (is_null(static::checkEmptyInputs($input, $parts))) {
+      if (empty(static::checkEmptyInputs($input, $parts))) {
         if (isset($input['ampm'])) {
           if ($input['ampm'] == 'pm' && $input['hour'] < 12) {
             $input['hour'] += 12;
@@ -267,7 +267,7 @@ public static function processDatelist(&$element, FormStateInterface $form_state
         '#attributes' => $element['#attributes'],
         '#options' => $options,
         '#required' => $element['#required'],
-        '#error_no_message' => TRUE,
+        '#error_no_message' => FALSE,
       );
     }
 
@@ -302,7 +302,7 @@ public static function validateDatelist(&$element, FormStateInterface $form_stat
     $input_exists = FALSE;
     $input = NestedArray::getValue($form_state->getValues(), $element['#parents'], $input_exists);
     if ($input_exists) {
-      $first_empty = static::checkEmptyInputs($input, $element['#date_part_order']);
+      $all_empty = static::checkEmptyInputs($input, $element['#date_part_order']);
 
       // If there's empty input and the field is not required, set it to empty.
       if (empty($input['year']) && empty($input['month']) && empty($input['day']) && !$element['#required']) {
@@ -312,9 +312,11 @@ public static function validateDatelist(&$element, FormStateInterface $form_stat
       elseif (empty($input['year']) && empty($input['month']) && empty($input['day']) && $element['#required']) {
         $form_state->setError($element, t('The %field date is required.'));
       }
-      elseif (!is_null($first_empty)) {
-        $message = t('The %field date is invalid. A value must be selected for %part.', array('%field' => !empty($element['#title']) ? $element['#title'] : '', '%part' => $first_empty));
-        $form_state->setError($element, $message);
+      elseif (!empty($all_empty)) {
+        foreach ( $all_empty as $value ){
+          $message = t('A value must be selected for %part.', array('%part' => $value));
+          $form_state->setError($element[$value], $message);
+        }
       }
       else {
         // If the input is valid, set it.
@@ -334,24 +336,25 @@ public static function validateDatelist(&$element, FormStateInterface $form_stat
    * Checks the input array for empty values.
    *
    * Input array keys are checked against values in the parts array. Elements
-   * not in the parts array are ignored. If no empty values are found, null is
-   * returned. Otherwise, returns the first key in the input array that has an
-   * empty value.
+   * not in the parts array are ignored. Returns an array representing elements
+   * from the input array that have no value. If no empty values are found,
+   * returned array is empty.
    *
    * @param array $input
-   *
+   *   Array of individual inputs to check for value
    * @param array $parts
-   *
-   * @return string
-   *
+   *   Array to check input against, ignoring elements not in this array
+   * @return array
+   *   Array of keys from the input array that have no value, may be empty
    */
   protected static function checkEmptyInputs($input, $parts) {
+    $empty_parts = [];
     foreach ($parts as $part) {
       if (empty($input[$part])) {
-        return $part;
+        $empty_parts[] = $part;
       }
     }
-    return null;
+    return $empty_parts;
   }
 
   /**
diff --git a/core/modules/datetime/src/Tests/DateTimeFieldTest.php b/core/modules/datetime/src/Tests/DateTimeFieldTest.php
index 7e02528..70ec207 100644
--- a/core/modules/datetime/src/Tests/DateTimeFieldTest.php
+++ b/core/modules/datetime/src/Tests/DateTimeFieldTest.php
@@ -504,7 +504,7 @@ function testDatelistWidget() {
 
     $this->drupalPostForm(NULL, $edit, t('Save'));
     $this->assertResponse(200);
-    $this->assertText('error has been found');
+    $this->assertTextPattern('/(error has)|(errors have) been found/', 'Date validation error found');
   }
 
   /**
diff --git a/core/tests/Drupal/Tests/Component/Datetime/DateTimePlusTest.php b/core/tests/Drupal/Tests/Component/Datetime/DateTimePlusTest.php
index 5291fc6..2592333 100644
--- a/core/tests/Drupal/Tests/Component/Datetime/DateTimePlusTest.php
+++ b/core/tests/Drupal/Tests/Component/Datetime/DateTimePlusTest.php
@@ -249,22 +249,6 @@ public function testDateTimezoneWithDateTimeObject() {
   }
 
   /**
-   * Tests the checkArray method.
-   *
-   * @param mixed $expected
-   *   Expected result of checkArray method
-   * @param array $date_value
-   *   Input argument for DateTimePlus::checkArray().
-   *
-   * @dataProvider providerTestCheckArray
-  *
-   * @covers ::checkArray
-   */
-  public function testCheckArray($expected, $date_value) {
-    $this->assertEquals($expected, DateTimePlus::checkArray($date_value));
-  }
-
-  /**
    * Provides data for date tests.
    *
    * @return array
@@ -549,32 +533,4 @@ public function providerTestDateTimestamp() {
     );
   }
 
-  /**
-   * Data provider for testCheckArray().
-   *
-   * @return array
-   *   An array of arrays, each containing:
-   *    - 'expected' - The expected result of DateTimePlusTest::checkArray().
-   *    - 'input' - Input for DateTimePlusTest::checkArray().
-   *
-   * @see testCheckArray()
-   */
-  public function providerTestCheckArray() {
-
-    $data = array(
-      // Checks for completion of date array
-      array(FALSE, array('year' => 2013, 'month' => '', 'day' => '', 'hour' => '', 'minute' => '')),
-      array(FALSE, array('year' => 2013, 'month' => '12', 'day' => '', 'hour' => '', 'minute' => '')),
-      array(FALSE, array('year' => 2013, 'month' => '12', 'day' => '11', 'hour' => '', 'minute' => '')),
-      array(FALSE, array('year' => 2013, 'month' => '12', 'day' => '11', 'hour' => '10', 'minute' => '')),
-      array(TRUE, array('year' => 2013, 'month' => '12', 'day' => '11', 'hour' => '10', 'minute' => '09')),
-
-      // Checks for invalid time pairings
-      array(FALSE, array('year' => 2013, 'month' => '12', 'day' => '11', 'hour' => '10', 'minute' => '61')),
-      array(FALSE, array('year' => 2013, 'month' => '12', 'day' => '11', 'hour' => '25', 'minute' => '09')),
-    );
-
-    return $data;
-  }
-
 }