diff --git a/core/config/schema/core.data_types.schema.yml b/core/config/schema/core.data_types.schema.yml
index ea67e43..0edc548 100644
--- a/core/config/schema/core.data_types.schema.yml
+++ b/core/config/schema/core.data_types.schema.yml
@@ -72,6 +72,7 @@ date_format:
   type: string
   label: 'Date format'
   translatable: true
+  locale context: 'PHP date format'
 
 # HTML color value.
 color_hex:
diff --git a/core/modules/locale/src/Tests/LocaleConfigTranslationTest.php b/core/modules/locale/src/Tests/LocaleConfigTranslationTest.php
index ac6bb2d..a28f996 100644
--- a/core/modules/locale/src/Tests/LocaleConfigTranslationTest.php
+++ b/core/modules/locale/src/Tests/LocaleConfigTranslationTest.php
@@ -92,7 +92,7 @@ public function testConfigTranslation() {
     $this->assertText($site_name, 'The translated site name is displayed after translations refreshed.');
 
     // Check default medium date format exists and create a translation for it.
-    $string = $this->storage->findString(array('source' => 'D, m/d/Y - H:i', 'context' => '', 'type' => 'configuration'));
+    $string = $this->storage->findString(array('source' => 'D, m/d/Y - H:i', 'context' => 'PHP date format', 'type' => 'configuration'));
     $this->assertTrue($string, 'Configuration date formats have been created upon installation.');
 
     // Translate using the UI so configuration is refreshed.