mysql> select now();
+---------------------+
| now()               |
+---------------------+
| 2009-05-30 16:54:29 |
+---------------------+
1 row in set (0.00 sec)

mysql> select now();
+---------------------+
| now()               |
+---------------------+
| 2009-05-30 20:01:43 |
+---------------------+
1 row in set (0.00 sec)

default-time-zone='+00:00'

SELECT @@global.time_zone;

SET GLOBAL time_zone = '+8:00';
SET GLOBAL time_zone = 'Europe/Helsinki';
SET @@global.time_zone = '+00:00';

SELECT @@session.time_zone;

SET time_zone = 'Europe/Helsinki';
SET time_zone = "+00:00";
SET @@session.time_zone = "+00:00";

SELECT TIMEDIFF(NOW(), UTC_TIMESTAMP);

SELECT UNIX_TIMESTAMP();
SELECT UNIX_TIMESTAMP(NOW());

SELECT UNIX_TIMESTAMP(`timestamp`) FROM `table_name`

SELECT UNIX_TIMESTAMP(CONVERT_TZ(`utc_datetime`, '+00:00', @@session.time_zone)) FROM `table_name`

SET time_zone = timezonename;

$ sudo dpkg-reconfigure tzdata`

`/etc/init.d/mysql restart`

SET GLOBAL time_zone = '+8:00';

value="jdbc:mysql://localhost:3306/dbname?serverTimezone=UTC"

SELECT @@global.time_zone, @@session.time_zone;

SET GLOBAL time_zone = "Asia/Calcutta";
SET time_zone = "+05:30";
SET @@session.time_zone = "+05:30";

root@Ubuntu# ls -la /usr/share/zoneinfo/US
total 8

drwxr-xr-x  2 root root 4096 Apr 10  2013 .
drwxr-xr-x 22 root root 4096 Apr 10  2013 ..
lrwxrwxrwx  1 root root   18 Jul  8 22:33 Alaska -> ../SystemV/YST9YDT
lrwxrwxrwx  1 root root   21 Jul  8 22:33 Aleutian -> ../posix/America/Adak
lrwxrwxrwx  1 root root   15 Jul  8 22:33 Arizona -> ../SystemV/MST7
lrwxrwxrwx  1 root root   18 Jul  8 22:33 Central -> ../SystemV/CST6CDT
lrwxrwxrwx  1 root root   18 Jul  8 22:33 Eastern -> ../SystemV/EST5EDT
lrwxrwxrwx  1 root root   37 Jul  8 22:33 East-Indiana -> ../posix/America/Indiana/Indianapolis
lrwxrwxrwx  1 root root   19 Jul  8 22:33 Hawaii -> ../Pacific/Honolulu
lrwxrwxrwx  1 root root   24 Jul  8 22:33 Indiana-Starke -> ../posix/America/Knox_IN
lrwxrwxrwx  1 root root   24 Jul  8 22:33 Michigan -> ../posix/America/Detroit
lrwxrwxrwx  1 root root   18 Jul  8 22:33 Mountain -> ../SystemV/MST7MDT
lrwxrwxrwx  1 root root   18 Jul  8 22:33 Pacific -> ../SystemV/PST8PDT
lrwxrwxrwx  1 root root   18 Jul  8 22:33 Pacific-New -> ../SystemV/PST8PDT
lrwxrwxrwx  1 root root   20 Jul  8 22:33 Samoa -> ../Pacific/Pago_Pago
root@Ubuntu#

SET time_zone='US/Eastern';

SET time_zone='EST5EDT';

mysql_tzinfo_to_sql /usr/share/zoneinfo | mysql -u root mysql

$offset="+10:00";
$db->exec("SET time_zone='".$offset."';");

$db->MySQLi->query("SET time_zone='".$offset."';");