** Setup **

SET @session_time_zone = @@SESSION.time_zone;
SET @global_time_zone = @@GLOBAL.time_zone;
CREATE TABLE t1 (a datetime);
CREATE TABLE t2 (a timestamp);
'#-----------------------------FN_DYNVARS_177_01--------------------#'
SET @@time_zone = DEFAULT;
SELECT @@time_zone;
@@time_zone
SYSTEM
SYSTEM Expected
'#-----------------------------FN_DYNVARS_177_02-------------------#'
SET @@time_zone = '+05:00';
SELECT @@time_zone;
@@time_zone
+05:00
+05:00 Expected
SET @@time_zone = '-01:00';
SELECT @@time_zone;
@@time_zone
-01:00
-01:00 Expected
SET @@time_zone = '+00:00';
SELECT @@time_zone;
@@time_zone
+00:00
+00:00 Expected
SET @@time_zone = '-00:00';
SELECT @@time_zone;
@@time_zone
+00:00
-00:00 Expected
'#-----------------------------FN_DYNVARS_177_03----------------#'
SET @@time_zone = '+00:00';
INSERT INTO t1 VALUES('2008-03-05 16:28:00');
INSERT INTO t1 VALUES('1970-01-01 00:05:00'),('1970-01-01 01:05:00');
INSERT INTO t2 VALUES(20080305162800);
INSERT INTO t2 VALUES(19730101235900);
INSERT INTO t2 VALUES('1970-01-01 00:05:00'),('1970-01-01 01:05:00');
INSERT INTO t2 VALUES(19700101000500);
SELECT a,UNIX_TIMESTAMP(a) FROM t1;
a	UNIX_TIMESTAMP(a)
2008-03-05 16:28:00	1204734480
1970-01-01 00:05:00	300
1970-01-01 01:05:00	3900
SELECT a,UNIX_TIMESTAMP(a) FROM t2;
a	UNIX_TIMESTAMP(a)
2008-03-05 16:28:00	1204734480
1973-01-01 23:59:00	94780740
1970-01-01 00:05:00	300
1970-01-01 01:05:00	3900
1970-01-01 00:05:00	300
SET @@time_zone = 'MET';
SELECT a,UNIX_TIMESTAMP(a) FROM t1;
a	UNIX_TIMESTAMP(a)
2008-03-05 16:28:00	1204730880
1970-01-01 00:05:00	NULL
1970-01-01 01:05:00	300
SELECT a,UNIX_TIMESTAMP(a) FROM t2;
a	UNIX_TIMESTAMP(a)
2008-03-05 17:28:00	1204734480
1973-01-02 00:59:00	94780740
1970-01-01 01:05:00	300
1970-01-01 02:05:00	3900
1970-01-01 01:05:00	300
SET @@time_zone = '+05:00';
SELECT a,UNIX_TIMESTAMP(a) FROM t1;
a	UNIX_TIMESTAMP(a)
2008-03-05 16:28:00	1204716480
1970-01-01 00:05:00	NULL
1970-01-01 01:05:00	NULL
SELECT a,UNIX_TIMESTAMP(a) FROM t2;
a	UNIX_TIMESTAMP(a)
2008-03-05 21:28:00	1204734480
1973-01-02 04:59:00	94780740
1970-01-01 05:05:00	300
1970-01-01 06:05:00	3900
1970-01-01 05:05:00	300
SET @@time_zone = '+06:00';
SELECT a,UNIX_TIMESTAMP(a) FROM t1;
a	UNIX_TIMESTAMP(a)
2008-03-05 16:28:00	1204712880
1970-01-01 00:05:00	NULL
1970-01-01 01:05:00	NULL
SELECT a,UNIX_TIMESTAMP(a) FROM t2;
a	UNIX_TIMESTAMP(a)
2008-03-05 22:28:00	1204734480
1973-01-02 05:59:00	94780740
1970-01-01 06:05:00	300
1970-01-01 07:05:00	3900
1970-01-01 06:05:00	300
SET @@time_zone = '+01:00';
SELECT a,UNIX_TIMESTAMP(a) FROM t1;
a	UNIX_TIMESTAMP(a)
2008-03-05 16:28:00	1204730880
1970-01-01 00:05:00	NULL
1970-01-01 01:05:00	300
SELECT a,UNIX_TIMESTAMP(a) FROM t2;
a	UNIX_TIMESTAMP(a)
2008-03-05 17:28:00	1204734480
1973-01-02 00:59:00	94780740
1970-01-01 01:05:00	300
1970-01-01 02:05:00	3900
1970-01-01 01:05:00	300
SET @@time_zone = '+02:00';
SELECT a,UNIX_TIMESTAMP(a) FROM t1;
a	UNIX_TIMESTAMP(a)
2008-03-05 16:28:00	1204727280
1970-01-01 00:05:00	NULL
1970-01-01 01:05:00	NULL
SELECT a,UNIX_TIMESTAMP(a) FROM t2;
a	UNIX_TIMESTAMP(a)
2008-03-05 18:28:00	1204734480
1973-01-02 01:59:00	94780740
1970-01-01 02:05:00	300
1970-01-01 03:05:00	3900
1970-01-01 02:05:00	300
SET @@time_zone = '+00:00';
SELECT a,UNIX_TIMESTAMP(a) FROM t1;
a	UNIX_TIMESTAMP(a)
2008-03-05 16:28:00	1204734480
1970-01-01 00:05:00	300
1970-01-01 01:05:00	3900
SELECT a,UNIX_TIMESTAMP(a) FROM t2;
a	UNIX_TIMESTAMP(a)
2008-03-05 16:28:00	1204734480
1973-01-01 23:59:00	94780740
1970-01-01 00:05:00	300
1970-01-01 01:05:00	3900
1970-01-01 00:05:00	300
SET @@time_zone = '+06:00';
SELECT a,UNIX_TIMESTAMP(a) FROM t1;
a	UNIX_TIMESTAMP(a)
2008-03-05 16:28:00	1204712880
1970-01-01 00:05:00	NULL
1970-01-01 01:05:00	NULL
SELECT a,UNIX_TIMESTAMP(a) FROM t2;
a	UNIX_TIMESTAMP(a)
2008-03-05 22:28:00	1204734480
1973-01-02 05:59:00	94780740
1970-01-01 06:05:00	300
1970-01-01 07:05:00	3900
1970-01-01 06:05:00	300
Potential Feature: upon recovery of timezone,
the original value of the timestamp should be recovered.
'#-----------------------------FN_DYNVARS_177_04--------------------#'
SET @@time_zone = '6';
ERROR HY000: Unknown or incorrect time zone: '6'
'#-----------------------------FN_DYNVARS_177_05---------------#'
SET GLOBAL time_zone = 'SYSTEM';
connect  con_int1,localhost,root,,;
connection con_int1;
SELECT @@SESSION.time_zone;
@@SESSION.time_zone
SYSTEM
SYSTEM Expected
SET SESSION time_zone = '+05:00';
connect  con_int2,localhost,root,,;
connection con_int2;
SELECT @@SESSION.time_zone;
@@SESSION.time_zone
SYSTEM
SYSTEM Expected
SET SESSION time_zone = '-10:00';
connection con_int2;
SELECT @@SESSION.time_zone;
@@SESSION.time_zone
-10:00
-10:00 Expected
connection con_int1;
SELECT @@SESSION.time_zone;
@@SESSION.time_zone
+05:00
+05:00 Expected
SELECT @@GLOBAL.time_zone;
@@GLOBAL.time_zone
SYSTEM
SYSTEM Expected
connection default;
disconnect con_int1;
disconnect con_int2;
SET @@SESSION.time_zone = @session_time_zone;
SET @@GLOBAL.time_zone = @global_time_zone;
DROP TABLE t1;
DROP TABLE t2;