Ajuda Erro

Bom galera estou criando meu site e veio a dar esse erro , quando eu entro na conta admin do meu site pelo "LOCALHOST"

Warning: date() [function.date]: 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 'America/Sao_Paulo' for '-3.0/no DST' instead inC:\xampp\htdocs\pot\OTS_Account.php on line 416

Warning: date() [function.date]: 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 'America/Sao_Paulo' for '-3.0/no DST' instead inC:\xampp\htdocs\pot\OTS_Account.php on line 416
 

Ja tentei de tudo mas nao consegui resolver , por favor me ajudem o quanto antes 

Nao sei se estou na area certa , pois sou novo aqui