Taken from gentoo portage.

diff -NrU5 pdftk-1.41.orig/java_libs/com/lowagie/text/pdf/PdfDate.java pdftk-1.41/java_libs/com/lowagie/text/pdf/PdfDate.java
--- pdftk-1.41.orig/java_libs/com/lowagie/text/pdf/PdfDate.java	2009-05-18 20:49:13.000000000 -0600
+++ pdftk-1.41/java_libs/com/lowagie/text/pdf/PdfDate.java	2009-05-18 20:51:36.000000000 -0600
@@ -74,11 +74,11 @@
 public class PdfDate extends PdfString {
     
     // ssteward; static builds of pdftk (Windows, gcc 3.3.1) would
     // omit this class because of its reference by reflection;
     // this treatment ensures that ld will include it
-    private static Class c1= gnu.java.locale.Calendar.class;
+    private static Class c1= java.util.Calendar.class;
 
     private static final int dateSpace[] = {Calendar.YEAR, 4, 0, Calendar.MONTH, 2, -1, Calendar.DAY_OF_MONTH, 2, 0,
         Calendar.HOUR_OF_DAY, 2, 0, Calendar.MINUTE, 2, 0, Calendar.SECOND, 2, 0};
     
     // constructors
