First stab.

Closes #3472861

src/EntityReferenceRevisionsOrphanPurger.php

@@ -153,6 +153,7 @@ class EntityReferenceRevisionsOrphanPurger {
    *   The context array.
    */
   public function deleteOrphansBatchOperation($entity_type_id, &$context) {
+    $batch_start = $this->time->getCurrentTime();
     $composite_type = $this->entityTypeManager->getDefinition($entity_type_id);
     $composite_revision_key = $composite_type->getKey('revision');
     /** @var \Drupal\Core\Entity\ContentEntityStorageInterface $composite_storage */
@@ -211,10 +212,10 @@ class EntityReferenceRevisionsOrphanPurger {
     }
     else {
       $context['finished'] = 1;
-      $context['results'][$entity_type_id]['end'] = $this->time->getRequestTime();
+      $context['results'][$entity_type_id]['end'] = $this->time->getCurrentTime();
     }
 
-    $interval = $this->dateFormatter->formatInterval($this->time->getRequestTime() - $context['results'][$entity_type_id]['start']);
+    $interval = $this->dateFormatter->formatDiff($batch_start, $this->time->getCurrentTime());
     $context['message'] = t('Checked @entity_type revisions for orphans: @current of @total in @interval (@deletions deleted)', [
       '@entity_type' => $composite_type->getLabel(),
       '@current' => $context['sandbox']['progress'],
@@ -277,7 +278,7 @@ class EntityReferenceRevisionsOrphanPurger {
       foreach ($results as $entity_type_id => $result) {
         if ($this->entityTypeManager->hasDefinition($entity_type_id)) {
           $entity_type = $this->entityTypeManager->getDefinition($entity_type_id);
-          $interval = $this->dateFormatter->formatInterval($result['end'] - $result['start']);
+          $interval = $this->dateFormatter->formatDiff($result['start'], $result['end']);
           $this->messenger->addMessage($this->t('@label: Deleted @revision_count revisions (@entity_count entities) in @interval.', [
             '@label' => $entity_type->getLabel(),
             '@revision_count' => $result['revision_count'],