diff --git a/lib/xlsx/xform/simple/date-xform.js b/lib/xlsx/xform/simple/date-xform.js
index 72c60fcee..e64c096d9 100644
--- a/lib/xlsx/xform/simple/date-xform.js
+++ b/lib/xlsx/xform/simple/date-xform.js
@@ -13,7 +13,13 @@ var DateXform = module.exports = function(options) {
   this.tag = options.tag;
   this.attr = options.attr;
   this.attrs = options.attrs;
-  this._format = options.format || function(dt) { return dt.toISOString(); };
+    this._format = options.format || function (dt) {
+    try {
+      return dt.toISOString();
+    } catch(e) {
+      return '';
+    }
+  };
   this._parse = options.parse || function(str) { return new Date(str); };
 };