--- old/src/java.base/share/classes/sun/util/locale/provider/CalendarDataUtility.java	2017-11-10 15:30:29.893545571 -0800
+++ new/src/java.base/share/classes/sun/util/locale/provider/CalendarDataUtility.java	2017-11-10 15:30:29.558539309 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -28,6 +28,7 @@
 import static java.util.Calendar.*;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Optional;
 import java.util.spi.CalendarDataProvider;
 import java.util.spi.CalendarNameProvider;
 
@@ -47,10 +48,34 @@
     }
 
     public static int retrieveFirstDayOfWeek(Locale locale) {
+        // Look for the Unicode Extension in the locale parameter
+        if (locale.hasExtensions()) {
+            String fw = locale.getUnicodeLocaleType("fw");
+            if (fw != null) {
+                switch (fw.toLowerCase(Locale.ROOT)) {
+                    case "mon":
+                        return MONDAY;
+                    case "tue":
+                        return TUESDAY;
+                    case "wed":
+                        return WEDNESDAY;
+                    case "thu":
+                        return THURSDAY;
+                    case "fri":
+                        return FRIDAY;
+                    case "sat":
+                        return SATURDAY;
+                    case "sun":
+                        return SUNDAY;
+                }
+            }
+        }
+
         LocaleServiceProviderPool pool =
                 LocaleServiceProviderPool.getPool(CalendarDataProvider.class);
         Integer value = pool.getLocalizedObject(CalendarWeekParameterGetter.INSTANCE,
-                                                locale, true, FIRST_DAY_OF_WEEK);
+                                                findRegionOverride(locale).orElse(locale),
+                                                true, FIRST_DAY_OF_WEEK);
         return (value != null && (value >= SUNDAY && value <= SATURDAY)) ? value : SUNDAY;
     }
 
@@ -58,7 +83,8 @@
         LocaleServiceProviderPool pool =
                 LocaleServiceProviderPool.getPool(CalendarDataProvider.class);
         Integer value = pool.getLocalizedObject(CalendarWeekParameterGetter.INSTANCE,
-                                                locale, true, MINIMAL_DAYS_IN_FIRST_WEEK);
+                                                findRegionOverride(locale).orElse(locale),
+                                                true, MINIMAL_DAYS_IN_FIRST_WEEK);
         return (value != null && (value >= 1 && value <= 7)) ? value : 1;
     }
 
@@ -102,6 +128,31 @@
         return map;
     }
 
+    /**
+     * Utility to look for a region override extension
+     */
+    public static Optional<Locale> findRegionOverride(Locale l) {
+        String rg = l.getUnicodeLocaleType("rg");
+        Locale override = null;
+
+        if (rg != null && rg.length() == 6) {
+            // UN M.49 code should not be allowed here
+            // cannot use regex here, as it could be a recursive call
+            rg = rg.toUpperCase(Locale.ROOT);
+            if (rg.charAt(0) >= 0x0041 &&
+                rg.charAt(0) <= 0x005A &&
+                rg.charAt(1) >= 0x0041 &&
+                rg.charAt(1) <= 0x005A &&
+                rg.substring(2).equals("ZZZZ")) {
+                override = new Locale.Builder().setLocale(l)
+                    .setRegion(rg.substring(0, 2))
+                    .build();
+            }
+        }
+
+        return Optional.ofNullable(override);
+    }
+
     static String normalizeCalendarType(String requestID) {
         String type;
         if (requestID.equals("gregorian") || requestID.equals("iso8601")) {
@@ -179,7 +230,7 @@
         }
     }
 
-     private static class CalendarWeekParameterGetter
+    private static class CalendarWeekParameterGetter
         implements LocaleServiceProviderPool.LocalizedObjectGetter<CalendarDataProvider,
                                                                    Integer> {
         private static final CalendarWeekParameterGetter INSTANCE =