Index: src/test/regress/expected/horology.out
===================================================================
--- src/test/regress/expected/horology.out.orig
+++ src/test/regress/expected/horology.out
@@ -652,26 +652,26 @@ SELECT (timestamp with time zone 'tomorr
 (1 row)
 
 -- timestamp with time zone, interval arithmetic around DST change
-SET TIME ZONE 'CST7CDT';
-SELECT timestamp with time zone '2005-04-02 12:00-07' + interval '1 day' as "Apr 3, 12:00";
+SET TIME ZONE 'CST6CDT';
+SELECT timestamp with time zone '2005-04-02 12:00-06' + interval '1 day' as "Apr 3, 12:00";
          Apr 3, 12:00         
 ------------------------------
  Sun Apr 03 12:00:00 2005 CDT
 (1 row)
 
-SELECT timestamp with time zone '2005-04-02 12:00-07' + interval '24 hours' as "Apr 3, 13:00";
+SELECT timestamp with time zone '2005-04-02 12:00-06' + interval '24 hours' as "Apr 3, 13:00";
          Apr 3, 13:00         
 ------------------------------
  Sun Apr 03 13:00:00 2005 CDT
 (1 row)
 
-SELECT timestamp with time zone '2005-04-03 12:00-06' - interval '1 day' as "Apr 2, 12:00";
+SELECT timestamp with time zone '2005-04-03 12:00-05' - interval '1 day' as "Apr 2, 12:00";
          Apr 2, 12:00         
 ------------------------------
  Sat Apr 02 12:00:00 2005 CST
 (1 row)
 
-SELECT timestamp with time zone '2005-04-03 12:00-06' - interval '24 hours' as "Apr 2, 11:00";
+SELECT timestamp with time zone '2005-04-03 12:00-05' - interval '24 hours' as "Apr 2, 11:00";
          Apr 2, 11:00         
 ------------------------------
  Sat Apr 02 11:00:00 2005 CST
Index: src/test/regress/pg_regress.c
===================================================================
--- src/test/regress/pg_regress.c.orig
+++ src/test/regress/pg_regress.c
@@ -64,7 +64,7 @@ static char *shellprog = SHELLPROG;
  */
 #ifndef WIN32
 const char *basic_diff_opts = "";
-const char *pretty_diff_opts = "-U3";
+const char *pretty_diff_opts = "-U5";
 #else
 const char *basic_diff_opts = "-w";
 const char *pretty_diff_opts = "-w -U3";
Index: src/test/regress/sql/horology.sql
===================================================================
--- src/test/regress/sql/horology.sql.orig
+++ src/test/regress/sql/horology.sql
@@ -122,11 +122,11 @@ SELECT (timestamp with time zone 'tomorr
 SELECT (timestamp with time zone 'tomorrow' > 'now') as "True";
 
 -- timestamp with time zone, interval arithmetic around DST change
-SET TIME ZONE 'CST7CDT';
-SELECT timestamp with time zone '2005-04-02 12:00-07' + interval '1 day' as "Apr 3, 12:00";
-SELECT timestamp with time zone '2005-04-02 12:00-07' + interval '24 hours' as "Apr 3, 13:00";
-SELECT timestamp with time zone '2005-04-03 12:00-06' - interval '1 day' as "Apr 2, 12:00";
-SELECT timestamp with time zone '2005-04-03 12:00-06' - interval '24 hours' as "Apr 2, 11:00";
+SET TIME ZONE 'CST6CDT';
+SELECT timestamp with time zone '2005-04-02 12:00-06' + interval '1 day' as "Apr 3, 12:00";
+SELECT timestamp with time zone '2005-04-02 12:00-06' + interval '24 hours' as "Apr 3, 13:00";
+SELECT timestamp with time zone '2005-04-03 12:00-05' - interval '1 day' as "Apr 2, 12:00";
+SELECT timestamp with time zone '2005-04-03 12:00-05' - interval '24 hours' as "Apr 2, 11:00";
 RESET TIME ZONE;