Index: org/quartz/AnnualCalendarTest.java
===================================================================
--- org/quartz/AnnualCalendarTest.java	(revision 739)
+++ org/quartz/AnnualCalendarTest.java	(working copy)
@@ -16,6 +16,7 @@
 package org.quartz;
 
 import java.util.Calendar;
+import java.util.Locale;
 import java.util.TimeZone;
 
 import org.quartz.impl.calendar.AnnualCalendar;
@@ -38,7 +39,7 @@
         
         c.setDescription("description");
         
-        Calendar cal = Calendar.getInstance(EST_TIME_ZONE);
+        Calendar cal = Calendar.getInstance(EST_TIME_ZONE, Locale.US);
         cal.clear();
         cal.set(2005, Calendar.JANUARY, 20, 10, 5, 15);
         
Index: org/quartz/NthIncludedDayTriggerTest.java
===================================================================
--- org/quartz/NthIncludedDayTriggerTest.java	(revision 739)
+++ org/quartz/NthIncludedDayTriggerTest.java	(working copy)
@@ -17,6 +17,7 @@
 
 import java.util.Calendar;
 import java.util.Date;
+import java.util.Locale;
 import java.util.TimeZone;
 
 
@@ -27,6 +28,19 @@
 public class NthIncludedDayTriggerTest extends SerializationTestSupport {
     private static final String[] VERSIONS = new String[] {"1.5.2"};
     
+    private Locale defaultLocale;
+
+    public void setUp() {
+        // These test assume a US locale, where firstDayOfWeek is Sunday.
+        // The default locale is preserved here, and restored after each test.
+        defaultLocale = Locale.getDefault();
+        Locale.setDefault(Locale.US);      
+    }
+
+    public void tearDown() {
+        Locale.setDefault(defaultLocale);      
+    }
+
     public void testGetFireTimeAfter() {
         Calendar startCalendar = Calendar.getInstance();
         startCalendar.set(2005, Calendar.JUNE, 1, 9, 30, 17);