diff --git a/lib/cartodb/models/dataview/histogram.js b/lib/cartodb/models/dataview/histogram.js
index b8b9085a..4499dd6c 100644
--- a/lib/cartodb/models/dataview/histogram.js
+++ b/lib/cartodb/models/dataview/histogram.js
@@ -14,8 +14,8 @@ var dateIntervalQueryTpl = dot.template([
     'WITH',
     'dates AS (',
     '    SELECT',
-    '        MAX({{=it.column}}) AS _end,',
-    '        MIN({{=it.column}}) AS _start',
+    '        MAX({{=it.column}}::timestamp) AS _end,',
+    '        MIN({{=it.column}}::timestamp) AS _start',
     '    FROM ({{=it.query}}) _cdb_source',
     '),',
     'interval_in_days AS (',