diff --git a/museums/museums.json b/museums/museums.json
index ab9a3542..c75b621d 100644
--- a/museums/museums.json
+++ b/museums/museums.json
@@ -20,7 +20,7 @@
     "columns": {
         "Period": {
             "type": "dimension",
-            "from_template": "gregorian-interval"
+            "from_template": "gregorian-instant"
         },
         "AREACD": {
             "type": "dimension",