Fix facet date granularity for the Drupal 7 search_api module version 1.6.

drupal_7_search_api_1_6_facet_date_granularity_fix.patch

diff --git a/contrib/search_api_facetapi/plugins/facetapi/query_type_date.inc b/contrib/search_api_facetapi/plugins/facetapi/query_type_date.inc
index 7277b56..0610d83 100644
--- a/contrib/search_api_facetapi/plugins/facetapi/query_type_date.inc
+++ b/contrib/search_api_facetapi/plugins/facetapi/query_type_date.inc
@@ -204,9 +204,15 @@ class SearchApiFacetapiDate extends SearchApiFacetapiTerm implements FacetapiQue
       }

       // Adds parent information if not already set.
-      if (NULL !== $parent && $parent != $new_value) {
-        $build[$parent]['#item_children'][$new_value] = &$build[$new_value];
-        $build[$new_value]['#item_parents'][$parent] = $parent;
+      if (NULL !== $parent) {
+        if ($parent != $new_value) {
+          $build[$parent]['#item_children'][$new_value] = &$build[$new_value];
+          $build[$new_value]['#item_parents'][$parent] = $parent;
+        }
+        // If the parent is the same as the value then it's the end.
+        else {
+          break;
+        }
       }
     }