Error page

Hi
Please view http://www.host.sofa...sponses_add.php
When you first load the page you get the below error.
On refreshing the page the same error goes. I have cleared all my event code but this does not resolve it. Any pointers to what the error could mean
Warning: strftime() [function.strftime]: It is not safe to rely on the system's timezone settings. You are required to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'UTC' for 'GMT/0.0/no DST' instead in /home/sofal137/public_html/demo/include/phpfunctions.php on line295<br style="font-family: 'Times New Roman'; font-size: medium; ">[size="+2"]php error happened[/size]

[size="+1"]Technical information[/size]Error type2Error descriptionCannot modify header information - headers already sent by (output started at /home/sofal137/public_html/demo/include/phpfunctions.php:295)URLwww.sofality.com/demo/responses_add.php?Error file/home/sofal137/public_html/demo/include/commonfunctions.phpError line5577SQL queryinsert into audit (datetime,ip,user,table,action,description) values ('2012-01-13 00:51:55','86.4.176.64','Guest','permissions','login','')More info