WordPress uses the date_default_timezone_set() function to set the server timezone. This is based on the timezone offset setting under Settings->General.
Check your setting to make sure it matches your timezone at: http://yourdomain.com/wp-admin/options-general.php
If changing your timezone via the setting doesn’t work, there’s probably nothing you can do to change this without touching your server configuration. You need to speak to your host and have them set your server timezone to the correct offset.
If you have access to your php.ini file, search for the following setting and set your timezone:
date.timezone = “”
Hope this helps you out.