MySQL Reference Manual :: A.4.6 Time Zone Problems

If you have a problem with SELECT NOW() returning values in GMT and not your local time, you have to tell the server your current time zone. The same applies if UNIX_TIMESTAMP() returns the wrong value. This should be done for the environment in which the server runs; for example, in mysqld_safe or mysql.server. See Appendix F, Environment Variables.

You can set the time zone for the server with the --timezone=timezone_name option to mysqld_safe. You can also set it by setting the TZ environment variable before you start mysqld.

The allowable values for --timezone or TZ are system-dependent. Consult your operating system documentation to see what values are acceptable.