diff --git a/papaparse.js b/papaparse.js
index 60ee489b..f32e55ea 100755
--- a/papaparse.js
+++ b/papaparse.js
@@ -1013,7 +1013,7 @@ License: MIT
 		var MAX_FLOAT = Math.pow(2, 53);
 		var MIN_FLOAT = -MAX_FLOAT;
 		var FLOAT = /^\s*-?(\d+\.?|\.\d+|\d+\.\d+)([eE][-+]?\d+)?\s*$/;
-		var ISO_DATE = /^(\d{4}-[01]\d-[0-3]\dT[0-2]\d:[0-5]\d:[0-5]\d\.\d+([+-][0-2]\d:[0-5]\d|Z))|(\d{4}-[01]\d-[0-3]\dT[0-2]\d:[0-5]\d:[0-5]\d([+-][0-2]\d:[0-5]\d|Z))|(\d{4}-[01]\d-[0-3]\dT[0-2]\d:[0-5]\d([+-][0-2]\d:[0-5]\d|Z))$/;
+		var ISO_DATE = /^((\d{4}-[01]\d-[0-3]\dT[0-2]\d:[0-5]\d:[0-5]\d\.\d+([+-][0-2]\d:[0-5]\d|Z))|(\d{4}-[01]\d-[0-3]\dT[0-2]\d:[0-5]\d:[0-5]\d([+-][0-2]\d:[0-5]\d|Z))|(\d{4}-[01]\d-[0-3]\dT[0-2]\d:[0-5]\d([+-][0-2]\d:[0-5]\d|Z)))$/;
 		var self = this;
 		var _stepCounter = 0;	// Number of times step was called (number of rows parsed)
 		var _rowCounter = 0;	// Number of rows that have been parsed so far