From 9eb085d191028c0541f2f678758119df7f7e6c53 Mon Sep 17 00:00:00 2001
From: chagelo <changeto104@gmail.com>
Date: Thu, 21 Nov 2024 18:52:10 +0800
Subject: [PATCH] * add `timezone(zone, timestamp)` testcases

Signed-off-by: chagelo <changeto104@gmail.com>
---
 src/expr/impl/src/scalar/timestamptz.rs       |   5 +-
 .../regress/data/expected/timestamptz.out     | 398 +++++++++++-------
 src/tests/regress/data/sql/timestamptz.sql    |  80 ++--
 3 files changed, 285 insertions(+), 198 deletions(-)

diff --git a/src/expr/impl/src/scalar/timestamptz.rs b/src/expr/impl/src/scalar/timestamptz.rs
index 0855ef086f6b..75a53f8a4b3c 100644
--- a/src/expr/impl/src/scalar/timestamptz.rs
+++ b/src/expr/impl/src/scalar/timestamptz.rs
@@ -80,10 +80,9 @@ pub fn timestamp_at_time_zone(input: Timestamp, time_zone: &str) -> Result<Times
     Ok(Timestamptz::from_micros(usec))
 }
 
-#[function("timezone(varchar, timestamp) -> timestamp")]
-pub fn timezone_timestamp_at_time_zone(time_zone: &str, input: Timestamp) -> Result<Timestamp> {
+#[function("timezone(varchar, timestamp) -> timestamptz")]
+pub fn timezone_timestamp_at_time_zone(time_zone: &str, input: Timestamp) -> Result<Timestamptz> {
     timestamp_at_time_zone(input, time_zone)
-        .map(|timestamptz| timestamptz.to_datetime_utc().naive_utc().into())
 }
 
 #[function("timezone(varchar, timestamptz) -> timestamp")]
diff --git a/src/tests/regress/data/expected/timestamptz.out b/src/tests/regress/data/expected/timestamptz.out
index 29fc1c4b089c..4677335daebb 100644
--- a/src/tests/regress/data/expected/timestamptz.out
+++ b/src/tests/regress/data/expected/timestamptz.out
@@ -2636,191 +2636,76 @@ SELECT '2014-10-26 02:00:00'::timestamp AT TIME ZONE 'MSK';
  2014-10-25 23:00:00+00
 (1 row)
 
-SELECT timezone('Asia/Shanghai', '2024-11-20 20:00:00 UTC'::timestamptz);
-      timezone       
----------------------
- 2024-11-21 04:00:00
-(1 row)
-
-SELECT timezone('Asia/Shanghai', '2023-02-28 20:00:00 UTC'::timestamptz);
-      timezone       
----------------------
- 2023-03-01 04:00:00
-(1 row)
-
-SELECT timezone('Asia/Shanghai', '2024-02-28 20:00:00 UTC'::timestamptz);
-      timezone       
----------------------
- 2024-02-29 04:00:00
-(1 row)
-
-SELECT timezone('Europe/Moscow', '2011-03-26 22:00:00 UTC'::timestamptz);
-      timezone       
----------------------
- 2011-03-27 01:00:00
-(1 row)
-
-SELECT timezone('Europe/Moscow', '2011-03-26 22:59:59 UTC'::timestamptz);
-      timezone       
----------------------
- 2011-03-27 01:59:59
-(1 row)
-
-SELECT timezone('Europe/Moscow', '2011-03-26 23:00:00 UTC'::timestamptz);
-      timezone       
----------------------
- 2011-03-27 03:00:00
-(1 row)
-
-SELECT timezone('Europe/Moscow', '2011-03-26 23:00:01 UTC'::timestamptz);
-      timezone       
----------------------
- 2011-03-27 03:00:01
-(1 row)
-
-SELECT timezone('Europe/Moscow', '2011-03-27 01:00:00 UTC'::timestamptz);
-      timezone       
----------------------
- 2011-03-27 05:00:00
-(1 row)
-
-SELECT timezone('Europe/Moscow', '2011-03-27 02:00:00 UTC'::timestamptz);
-      timezone       
----------------------
- 2011-03-27 06:00:00
-(1 row)
-
-SELECT timezone('Europe/Moscow', '2011-03-27 02:59:59 UTC'::timestamptz);
-      timezone       
----------------------
- 2011-03-27 06:59:59
-(1 row)
-
-SELECT timezone('Europe/Moscow', '2011-03-27 03:00:00 UTC'::timestamptz);
-      timezone       
----------------------
- 2011-03-27 07:00:00
-(1 row)
-
-SELECT timezone('MSK', '2011-03-26 22:00:00 UTC'::timestamptz);
-      timezone       
----------------------
- 2011-03-27 01:00:00 
-(1 row)
-
-SELECT timezone('MSK', '2011-03-26 22:59:59 UTC'::timestamptz);
-      timezone       
----------------------
- 2011-03-27 01:59:59
-(1 row)
-
-SELECT timezone('MSK', '2011-03-26 23:00:00 UTC'::timestamptz);
-      timezone       
----------------------
- 2011-03-27 03:00:00
-(1 row)
-
-SELECT timezone('MSK', '2011-03-26 23:00:01 UTC'::timestamptz);
-      timezone       
----------------------
- 2011-03-27 03:00:01
-(1 row)
-
-SELECT timezone('MSK', '2011-03-27 01:00:00 UTC'::timestamptz);
-      timezone       
----------------------
- 2011-03-27 05:00:00
-(1 row)
-
-SELECT timezone('MSK', '2011-03-27 02:00:00 UTC'::timestamptz);
-      timezone       
----------------------
- 2011-03-27 06:00:00
-(1 row)
-
-SELECT timezone('MSK', '2011-03-27 02:59:59 UTC'::timestamptz);
-      timezone       
----------------------
- 2011-03-27 06:59:59
-(1 row)
-
-SELECT timezone('MSK', '2011-03-27 03:00:00 UTC'::timestamptz);
-      timezone       
----------------------
- 2011-03-27 07:00:00
-(1 row)
-
-
-SELECT timezone('Europe/Moscow', '2014-10-25 21:59:59 UTC'::timestamptz);
-      timezone       
----------------------
- 2014-10-26 01:59:59
+SELECT timezone('Europe/Moscow', '2011-03-27 02:00:00'::timestamp);
+         timezone          
+---------------------------
+ 2011-03-26 23:00:00+00
 (1 row)
 
-SELECT timezone('Europe/Moscow', '2014-10-25 22:00:00 UTC'::timestamptz);
-      timezone       
----------------------
- 2014-10-26 01:00:00
+SELECT timezone('Europe/Moscow', '2011-03-27 02:59:59'::timestamp);
+         timezone          
+---------------------------
+ 2011-03-26 23:59:59+00
 (1 row)
 
-SELECT timezone('Europe/Moscow', '2014-10-25 22:59:59 UTC'::timestamptz);
-      timezone       
----------------------
- 2014-10-26 01:59:59
+SELECT timezone('Europe/Moscow', '2011-03-27 03:00:00'::timestamp);
+         timezone          
+---------------------------
+ 2011-03-26 23:00:00+00
 (1 row)
 
-SELECT timezone('Europe/Moscow', '2014-10-25 23:00:00 UTC'::timestamptz);
-      timezone       
----------------------
- 2014-10-26 02:00:00
+SELECT timezone('MSK', '2011-03-27 02:00:00'::timestamp);
+        timezone        
+------------------------
+ 2011-03-26 22:00:00+00
 (1 row)
 
-SELECT timezone('Europe/Moscow', '2014-10-25 23:00:01 UTC'::timestamptz);
-      timezone       
----------------------
- 2014-10-26 02:00:01
+SELECT timezone('MSK', '2011-03-27 02:59:59'::timestamp);
+        timezone        
+------------------------
+ 2011-03-26 22:59:59+00
 (1 row)
 
-SELECT timezone('Europe/Moscow', '2014-10-26 02:00:01 UTC'::timestamptz);
-      timezone       
----------------------
- 2014-10-26 05:00:01
+SELECT timezone('MSK', '2011-03-27 03:00:00'::timestamp);
+        timezone        
+------------------------
+ 2011-03-26 23:00:00+00
 (1 row)
 
-SELECT timezone('MSK', '2014-10-25 21:59:59 UTC'::timestamptz);
-      timezone       
----------------------
- 2014-10-26 01:59:59
+SELECT timezone('Europe/Moscow', '2014-10-26 00:59:59'::timestamp);
+         timezone          
+---------------------------
+ 2014-10-25 20:59:59+00
 (1 row)
 
-SELECT timezone('MSK', '2014-10-25 22:00:00 UTC'::timestamptz);
-      timezone       
----------------------
- 2014-10-26 01:00:00
+SELECT timezone('Europe/Moscow', '2014-10-26 01:00:00'::timestamp);
+         timezone          
+---------------------------
+ 2014-10-25 22:00:00+00
 (1 row)
 
-SELECT timezone('MSK', '2014-10-25 22:59:59 UTC'::timestamptz);
-      timezone       
----------------------
- 2014-10-26 01:59:59
+SELECT timezone('Europe/Moscow', '2014-10-26 01:00:01'::timestamp);
+         timezone          
+---------------------------
+ 2014-10-25 22:00:01+00
 (1 row)
 
-SELECT timezone('MSK', '2014-10-25 23:00:00 UTC'::timestamptz);
-      timezone       
----------------------
- 2014-10-26 02:00:00
+SELECT timezone('MSK', '2014-10-26 00:59:59'::timestamp);
+        timezone        
+------------------------
+ 2014-10-25 20:59:59+00
 (1 row)
 
-SELECT timezone('MSK', '2014-10-25 23:00:01 UTC'::timestamptz);
-      timezone       
----------------------
- 2014-10-26 02:00:01
+SELECT timezone('MSK', '2014-10-26 01:00:00'::timestamp);
+        timezone        
+------------------------
+ 2014-10-25 22:00:00+00
 (1 row)
 
-SELECT timezone('MSK', '2014-10-26 02:00:01 UTC'::timestamptz);
-      timezone       
----------------------
- 2014-10-26 05:00:01
+SELECT timezone('MSK', '2014-10-26 01:00:01'::timestamp);
+        timezone        
+------------------------
+ 2014-10-25 22:00:01+00
 (1 row)
 
 SELECT make_timestamptz(2014, 10, 26, 0, 0, 0, 'MSK');
@@ -3094,6 +2979,193 @@ SELECT '2014-10-25 23:00:00 UTC'::timestamptz AT TIME ZONE 'MSK';
  2014-10-26 02:00:00
 (1 row)
 
+SELECT timezone('Asia/Shanghai', '2024-11-20 20:00:00 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2024-11-21 04:00:00
+(1 row)
+
+SELECT timezone('Asia/Shanghai', '2023-02-28 20:00:00 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2023-03-01 04:00:00
+(1 row)
+
+SELECT timezone('Asia/Shanghai', '2024-02-28 20:00:00 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2024-02-29 04:00:00
+(1 row)
+
+SELECT timezone('Europe/Moscow', '2011-03-26 22:00:00 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2011-03-27 01:00:00
+(1 row)
+
+SELECT timezone('Europe/Moscow', '2011-03-26 22:59:59 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2011-03-27 01:59:59
+(1 row)
+
+SELECT timezone('Europe/Moscow', '2011-03-26 23:00:00 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2011-03-27 03:00:00
+(1 row)
+
+SELECT timezone('Europe/Moscow', '2011-03-26 23:00:01 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2011-03-27 03:00:01
+(1 row)
+
+SELECT timezone('Europe/Moscow', '2011-03-27 01:00:00 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2011-03-27 05:00:00
+(1 row)
+
+SELECT timezone('Europe/Moscow', '2011-03-27 02:00:00 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2011-03-27 06:00:00
+(1 row)
+
+SELECT timezone('Europe/Moscow', '2011-03-27 02:59:59 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2011-03-27 06:59:59
+(1 row)
+
+SELECT timezone('Europe/Moscow', '2011-03-27 03:00:00 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2011-03-27 07:00:00
+(1 row)
+
+SELECT timezone('MSK', '2011-03-26 22:00:00 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2011-03-27 01:00:00 
+(1 row)
+
+SELECT timezone('MSK', '2011-03-26 22:59:59 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2011-03-27 01:59:59
+(1 row)
+
+SELECT timezone('MSK', '2011-03-26 23:00:00 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2011-03-27 03:00:00
+(1 row)
+
+SELECT timezone('MSK', '2011-03-26 23:00:01 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2011-03-27 03:00:01
+(1 row)
+
+SELECT timezone('MSK', '2011-03-27 01:00:00 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2011-03-27 05:00:00
+(1 row)
+
+SELECT timezone('MSK', '2011-03-27 02:00:00 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2011-03-27 06:00:00
+(1 row)
+
+SELECT timezone('MSK', '2011-03-27 02:59:59 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2011-03-27 06:59:59
+(1 row)
+
+SELECT timezone('MSK', '2011-03-27 03:00:00 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2011-03-27 07:00:00
+(1 row)
+
+
+SELECT timezone('Europe/Moscow', '2014-10-25 21:59:59 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2014-10-26 01:59:59
+(1 row)
+
+SELECT timezone('Europe/Moscow', '2014-10-25 22:00:00 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2014-10-26 01:00:00
+(1 row)
+
+SELECT timezone('Europe/Moscow', '2014-10-25 22:59:59 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2014-10-26 01:59:59
+(1 row)
+
+SELECT timezone('Europe/Moscow', '2014-10-25 23:00:00 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2014-10-26 02:00:00
+(1 row)
+
+SELECT timezone('Europe/Moscow', '2014-10-25 23:00:01 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2014-10-26 02:00:01
+(1 row)
+
+SELECT timezone('Europe/Moscow', '2014-10-26 02:00:01 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2014-10-26 05:00:01
+(1 row)
+
+SELECT timezone('MSK', '2014-10-25 21:59:59 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2014-10-26 01:59:59
+(1 row)
+
+SELECT timezone('MSK', '2014-10-25 22:00:00 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2014-10-26 01:00:00
+(1 row)
+
+SELECT timezone('MSK', '2014-10-25 22:59:59 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2014-10-26 01:59:59
+(1 row)
+
+SELECT timezone('MSK', '2014-10-25 23:00:00 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2014-10-26 02:00:00
+(1 row)
+
+SELECT timezone('MSK', '2014-10-25 23:00:01 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2014-10-26 02:00:01
+(1 row)
+
+SELECT timezone('MSK', '2014-10-26 02:00:01 UTC'::timestamptz);
+      timezone       
+---------------------
+ 2014-10-26 05:00:01
+(1 row)
+
 --
 -- Test that AT TIME ZONE isn't misoptimized when using an index (bug #14504)
 --
diff --git a/src/tests/regress/data/sql/timestamptz.sql b/src/tests/regress/data/sql/timestamptz.sql
index 296e5021a849..c1b34a3503a1 100644
--- a/src/tests/regress/data/sql/timestamptz.sql
+++ b/src/tests/regress/data/sql/timestamptz.sql
@@ -480,41 +480,21 @@ SELECT '2014-10-26 01:00:00'::timestamp AT TIME ZONE 'MSK';
 SELECT '2014-10-26 01:00:01'::timestamp AT TIME ZONE 'MSK';
 SELECT '2014-10-26 02:00:00'::timestamp AT TIME ZONE 'MSK';
 
-SELECT timezone('Asia/Shanghai', '2024-11-20 20:00:00 UTC'::timestamptz);
-SELECT timezone('Asia/Shanghai', '2023-02-28 20:00:00 UTC'::timestamptz);
-SELECT timezone('Asia/Shanghai', '2024-02-28 20:00:00 UTC'::timestamptz);
+SELECT timezone('Europe/Moscow', '2011-03-27 02:00:00'::timestamp);
+SELECT timezone('Europe/Moscow', '2011-03-27 02:59:59'::timestamp);
+SELECT timezone('Europe/Moscow', '2011-03-27 03:00:00'::timestamp);
 
-SELECT timezone('Europe/Moscow', '2011-03-26 22:00:00 UTC'::timestamptz);
-SELECT timezone('Europe/Moscow', '2011-03-26 22:59:59 UTC'::timestamptz);
-SELECT timezone('Europe/Moscow', '2011-03-26 23:00:00 UTC'::timestamptz);
-SELECT timezone('Europe/Moscow', '2011-03-26 23:00:01 UTC'::timestamptz);
-SELECT timezone('Europe/Moscow', '2011-03-27 01:00:00 UTC'::timestamptz);
-SELECT timezone('Europe/Moscow', '2011-03-27 02:00:00 UTC'::timestamptz);
-SELECT timezone('Europe/Moscow', '2011-03-27 02:59:59 UTC'::timestamptz);
-SELECT timezone('Europe/Moscow', '2011-03-27 03:00:00 UTC'::timestamptz);
-
-SELECT timezone('MSK', '2011-03-26 22:00:00 UTC'::timestamptz);
-SELECT timezone('MSK', '2011-03-26 22:59:59 UTC'::timestamptz);
-SELECT timezone('MSK', '2011-03-26 23:00:00 UTC'::timestamptz);
-SELECT timezone('MSK', '2011-03-26 23:00:01 UTC'::timestamptz);
-SELECT timezone('MSK', '2011-03-27 01:00:00 UTC'::timestamptz);
-SELECT timezone('MSK', '2011-03-27 02:00:00 UTC'::timestamptz);
-SELECT timezone('MSK', '2011-03-27 02:59:59 UTC'::timestamptz);
-SELECT timezone('MSK', '2011-03-27 03:00:00 UTC'::timestamptz);
+SELECT timezone('MSK', '2011-03-27 02:00:00'::timestamp);
+SELECT timezone('MSK', '2011-03-27 02:59:59'::timestamp);
+SELECT timezone('MSK', '2011-03-27 03:00:00'::timestamp);
 
-SELECT timezone('Europe/Moscow', '2014-10-25 21:59:59 UTC'::timestamptz);
-SELECT timezone('Europe/Moscow', '2014-10-25 22:00:00 UTC'::timestamptz);
-SELECT timezone('Europe/Moscow', '2014-10-25 22:59:59 UTC'::timestamptz);
-SELECT timezone('Europe/Moscow', '2014-10-25 23:00:00 UTC'::timestamptz);
-SELECT timezone('Europe/Moscow', '2014-10-25 23:00:01 UTC'::timestamptz);
-SELECT timezone('Europe/Moscow', '2014-10-26 02:00:01 UTC'::timestamptz);
+SELECT timezone('Europe/Moscow', '2014-10-26 00:59:59'::timestamp);
+SELECT timezone('Europe/Moscow', '2014-10-26 01:00:00'::timestamp);
+SELECT timezone('Europe/Moscow', '2014-10-26 01:00:01'::timestamp);
 
-SELECT timezone('MSK', '2014-10-25 21:59:59 UTC'::timestamptz);
-SELECT timezone('MSK', '2014-10-25 22:00:00 UTC'::timestamptz);
-SELECT timezone('MSK', '2014-10-25 22:59:59 UTC'::timestamptz);
-SELECT timezone('MSK', '2014-10-25 23:00:00 UTC'::timestamptz);
-SELECT timezone('MSK', '2014-10-25 23:00:01 UTC'::timestamptz);
-SELECT timezone('MSK', '2014-10-26 02:00:01 UTC'::timestamptz);
+SELECT timezone('MSK', '2014-10-26 00:59:59'::timestamp);
+SELECT timezone('MSK', '2014-10-26 01:00:00'::timestamp);
+SELECT timezone('MSK', '2014-10-26 01:00:01'::timestamp);
 
 SELECT make_timestamptz(2014, 10, 26, 0, 0, 0, 'MSK');
 SELECT make_timestamptz(2014, 10, 26, 1, 0, 0, 'MSK');
@@ -577,6 +557,42 @@ SELECT '2014-10-25 22:00:00 UTC'::timestamptz AT TIME ZONE 'MSK';
 SELECT '2014-10-25 22:00:01 UTC'::timestamptz AT TIME ZONE 'MSK';
 SELECT '2014-10-25 23:00:00 UTC'::timestamptz AT TIME ZONE 'MSK';
 
+SELECT timezone('Asia/Shanghai', '2024-11-20 20:00:00 UTC'::timestamptz);
+SELECT timezone('Asia/Shanghai', '2023-02-28 20:00:00 UTC'::timestamptz);
+SELECT timezone('Asia/Shanghai', '2024-02-28 20:00:00 UTC'::timestamptz);
+
+SELECT timezone('Europe/Moscow', '2011-03-26 22:00:00 UTC'::timestamptz);
+SELECT timezone('Europe/Moscow', '2011-03-26 22:59:59 UTC'::timestamptz);
+SELECT timezone('Europe/Moscow', '2011-03-26 23:00:00 UTC'::timestamptz);
+SELECT timezone('Europe/Moscow', '2011-03-26 23:00:01 UTC'::timestamptz);
+SELECT timezone('Europe/Moscow', '2011-03-27 01:00:00 UTC'::timestamptz);
+SELECT timezone('Europe/Moscow', '2011-03-27 02:00:00 UTC'::timestamptz);
+SELECT timezone('Europe/Moscow', '2011-03-27 02:59:59 UTC'::timestamptz);
+SELECT timezone('Europe/Moscow', '2011-03-27 03:00:00 UTC'::timestamptz);
+
+SELECT timezone('MSK', '2011-03-26 22:00:00 UTC'::timestamptz);
+SELECT timezone('MSK', '2011-03-26 22:59:59 UTC'::timestamptz);
+SELECT timezone('MSK', '2011-03-26 23:00:00 UTC'::timestamptz);
+SELECT timezone('MSK', '2011-03-26 23:00:01 UTC'::timestamptz);
+SELECT timezone('MSK', '2011-03-27 01:00:00 UTC'::timestamptz);
+SELECT timezone('MSK', '2011-03-27 02:00:00 UTC'::timestamptz);
+SELECT timezone('MSK', '2011-03-27 02:59:59 UTC'::timestamptz);
+SELECT timezone('MSK', '2011-03-27 03:00:00 UTC'::timestamptz);
+
+SELECT timezone('Europe/Moscow', '2014-10-25 21:59:59 UTC'::timestamptz);
+SELECT timezone('Europe/Moscow', '2014-10-25 22:00:00 UTC'::timestamptz);
+SELECT timezone('Europe/Moscow', '2014-10-25 22:59:59 UTC'::timestamptz);
+SELECT timezone('Europe/Moscow', '2014-10-25 23:00:00 UTC'::timestamptz);
+SELECT timezone('Europe/Moscow', '2014-10-25 23:00:01 UTC'::timestamptz);
+SELECT timezone('Europe/Moscow', '2014-10-26 02:00:01 UTC'::timestamptz);
+
+SELECT timezone('MSK', '2014-10-25 21:59:59 UTC'::timestamptz);
+SELECT timezone('MSK', '2014-10-25 22:00:00 UTC'::timestamptz);
+SELECT timezone('MSK', '2014-10-25 22:59:59 UTC'::timestamptz);
+SELECT timezone('MSK', '2014-10-25 23:00:00 UTC'::timestamptz);
+SELECT timezone('MSK', '2014-10-25 23:00:01 UTC'::timestamptz);
+SELECT timezone('MSK', '2014-10-26 02:00:01 UTC'::timestamptz);
+
 --
 -- Test that AT TIME ZONE isn't misoptimized when using an index (bug #14504)
 --