Using Timestamp data with UTC type.

1. Using Function 

[root@oraclelinux6.localdomain][test]> select @@global.time_zone, @@session.time_zone;
+--------------------+---------------------+
| @@global.time_zone | @@session.time_zone |
+--------------------+---------------------+
| SYSTEM             | SYSTEM              |
+--------------------+---------------------+
1 row in set (0.01 sec)

[root@oraclelinux6.localdomain][test]> select now();
+---------------------+
| now()               |
+---------------------+
| 2015-06-24 23:41:50 |
+---------------------+
1 row in set (0.00 sec)

[root@oraclelinux6.localdomain][test]> create table test ( ts timestamp not null) ;
Query OK, 0 rows affected (0.01 sec)

[root@oraclelinux6.localdomain][test]> insert into test( ts) values (utc_timestamp());
Query OK, 1 row affected (0.00 sec)

[root@oraclelinux6.localdomain][test]> select * from test;
+---------------------+
| ts                  |
+---------------------+
| 2015-06-25 06:41:39 |
+---------------------+
1 row in set (0.00 sec)

2. Setting time_zone value 

[root@oraclelinux6.localdomain][test]> select @@global.time_zone, @@session.time_zone;
+--------------------+---------------------+
| @@global.time_zone | @@session.time_zone |
+--------------------+---------------------+
| SYSTEM             | SYSTEM              |
+--------------------+---------------------+
1 row in set (0.01 sec)

[root@oraclelinux6.localdomain][test]> set session time_zone='+00:00';
Query OK, 0 rows affected (0.00 sec)

[root@oraclelinux6.localdomain][test]> select now();
+---------------------+
| now()               |
+---------------------+
| 2015-06-25 06:44:20 |
+---------------------+
1 row in set (0.01 sec)

[root@oraclelinux6.localdomain][test]> set session time_zone='SYSTEM';
Query OK, 0 rows affected (0.00 sec)

[root@oraclelinux6.localdomain][test]> select now();
+---------------------+
| now()               |
+---------------------+
| 2015-06-24 23:45:39 |
+---------------------+
1 row in set (0.00 sec)

[root@oraclelinux6.localdomain][test]> system date;
Wed Jun 24 23:45:47 PDT 2015
[root@oraclelinux6.localdomain][test]>

3. Loading Named Time Zone table 

You can use system's local's zoneinfo database. Or, You can use package that is available for download at the MySQL Developer Zone.

3.1 Using system's zoneinfo database. 

shell> cd /db/mysql/bin
shell> ./mysql_tzinfo_to_sql /usr/share/zoneino >> /tmp/timezone.sql
shell> ./mysql -p -u root
[root@oraclelinux6.localdomain][]> source /tmp/timezone.sql  

3.2 Using a package that is available for download at the MySQL Developer Zone. 

You Can see a package file list this url.
http://dev.mysql.com/downloads/timezones.html
Select one package for you. And then, Load MySQL's mysql schema.

[root@oraclelinux6.localdomain][]> use mysql;
[root@oraclelinux6.localdomain][mysql]> source /tmp/timezone_posix.sql

DATETIME and TIMESTAMP

1. DATA Type

DATETIME and TIMESTAMP datatype have year,month,day,hour,minute and seconds. Additionally, They can save fraction of second. They use data format with YYYY-MM-DD HH:MM:SS[.fraction]. DATETIME can save value from '1000-01-01 00:00:00.000000' to '9999-12-31 23:59:59.999999' . TIMESTAMP can save value from '1970-01-01 00:00:01.000000' UTC to '2038-01-19 03:14:07.99999' UTC.

2. Different DATETIME and TIMESTAMP 

DATETIME have no timezone information. TIMESTAMP have timezone information with time_zone system  variables. In detail,  TIMESTAMP have date and time data in UTC timezone. So, Before saving date and time data, MySQL convert timezone to UTC.

3. Setting default value 

After MySQL Version 5.6, DATETIME setting default time value.

CREATE TABLE t1 (
  ts TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  dt DATETIME DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
);