--- ./src/java/org/apache/poi/hssf/usermodel/HSSFDateUtil.java.orig	2008-02-07 12:02:57.000000000 +0100
+++ ./src/java/org/apache/poi/hssf/usermodel/HSSFDateUtil.java	2008-02-07 12:29:17.000000000 +0100
@@ -210,7 +210,7 @@
     	
     	// Otherwise, check it's only made up of:
     	//  y m d - / ,
-    	if(fs.matches("^[ymd\\-/, ]+$")) {
+    	if(fs.matches("^[yYmMdDhHsS\\-/,. :]+$")) {
     		return true;
     	}