diff --git a/core_search_facets/src/Plugin/facets/query_type/CoreNodeSearchDate.php b/core_search_facets/src/Plugin/facets/query_type/CoreNodeSearchDate.php
index ce894f7..bd2a318 100644
--- a/core_search_facets/src/Plugin/facets/query_type/CoreNodeSearchDate.php
+++ b/core_search_facets/src/Plugin/facets/query_type/CoreNodeSearchDate.php
@@ -151,7 +151,7 @@ class CoreNodeSearchDate extends QueryTypePluginBase {
       $range_end = [];
       $previous = NULL;
       foreach (array_unique($dates) as $date) {
-        if (is_null($previous)) {
+        if (!is_null($previous)) {
           $range_end[$previous] = $date_handler->getNextDateIncrement($previous, $gap);
         }
         $previous = $date;
diff --git a/src/Utility/FacetsDateHandler.php b/src/Utility/FacetsDateHandler.php
index ae9a703..7b0b522 100644
--- a/src/Utility/FacetsDateHandler.php
+++ b/src/Utility/FacetsDateHandler.php
@@ -62,7 +62,7 @@ class FacetsDateHandler {
   /**
    * Regex pattern for date ranges.
    */
-  const FACETS_REGEX_DATE_RANGE = '/^\[(/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})Z$/) TO (/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})Z$/)\]$/';
+  const FACETS_REGEX_DATE_RANGE = '/^\[((\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})Z) TO ((\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})Z)\]$/';
 
   /**
    * The date formatting service.