TimeZone not set correctly - php

Question

I have a problem, I'm using mysql with PHP and I have in my database timestamp columns that are automatically set on update by the current timestamp. But when I'm trying to insert rows into the table the rows are added with timestamp different from my current time (before two hours) I have the EST timezone.
I've checked the timezone for the database and it is System and when I searched for that I read that it depeneds on the machine that is connecting, but my machine has EST time, so can anyone explain why I'm having this? and what can I do to set the current timestamp for my database to EST?

Answer 1

I've personally found it to be a lot more reliable to set the timezone in PHP, then grab the timestamp there and pass this to your MySQL query.
Something like:
date_default_timezone_set('America/New_York');
$curtimestamp = date('Y-m-d G:i:s', time());
Then use the value of $curtimestamp in your queries.

Answer 2

The documentation may have been unclear.
time_zone=SYSTEM means that the MySQL Server time zone is derived from the host that the MySQL Server is running on, not the client system.
So, if the time zone on the MySQL server host is different from the time zone of the client host, that explains the behavior that you observe.
Each client (database session) has its own time_zone setting. When the connection is established, the setting is derived from the "default" time zone for the MySQL server.
The setting of this variable determines how DATETIME and TIMESTAMP values are interpreted, when values are sent to the database from the client, AND when existing values are pulled from the database.
A client can issue a SET time_zone statement to change the time_zone for the database session, e.g.
SET time_zone=CST6CDT
(Note that to use named values for time zones, the time_zone% tables in the mysql database must be populated.)
To set the "default" time_zone that will be used for new database connections, you can set the "global" time_zone variable:
SET GLOBAL time_zone=
(This change requires SUPER privilege, and it impacts ALL new database connections to the entire instance. Normally, this value is set in the MySQL server configuration file.)
For TIMESTAMP columns, MySQL stores those as UTC. The values returned to the client depend on the setting of the client time_zone. As a simple demonstration:
mysql> CREATE TABLE mytest
-> ( id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY
-> , ts TIMESTAMP DEFAULT CURRENT_TIMESTAMP
-> );
Query OK, 0 rows affected (0.11 sec)
mysql> SHOW VARIABLES LIKE 'time_zone';
+---------------+--------+
| Variable_name | Value |
+---------------+--------+
| time_zone | +00:00 |
+---------------+--------+
1 row in set (0.00 sec)
mysql> INSERT INTO mytest (id) VALUES (NULL);
Query OK, 1 row affected (0.00 sec)
mysql> SELECT * FROM mytest;
+----+---------------------+
| id | ts |
+----+---------------------+
| 1 | 2015-01-09 15:41:25 |
+----+---------------------+
1 row in set (0.00 sec)
mysql> SET time_zone = 'CST6CDT';
Query OK, 0 rows affected (0.00 sec)
mysql> SELECT * FROM mytest;
+----+---------------------+
| id | ts |
+----+---------------------+
| 1 | 2015-01-09 09:41:25 |
+----+---------------------+
1 row in set (0.00 sec)
mysql> INSERT INTO mytest (id) VALUES (NULL);
Query OK, 1 row affected (0.00 sec)
mysql> SELECT * FROM mytest;
+----+---------------------+
| id | ts |
+----+---------------------+
| 1 | 2015-01-09 09:41:25 |
| 2 | 2015-01-09 09:41:25 |
+----+---------------------+
2 rows in set (0.00 sec)
mysql> SET time_zone = 'EST5EDT';
Query OK, 0 rows affected (0.00 sec)
mysql> SELECT * FROM mytest;
+----+---------------------+
| id | ts |
+----+---------------------+
| 1 | 2015-01-09 10:41:25 |
| 2 | 2015-01-09 10:41:25 |
+----+---------------------+
2 rows in set (0.00 sec)