The documentation should have this info. The function time() returns always timestamp that is timezone independent (=UTC).

<?php 
date_default_timezone_set("UTC"); 
echo "UTC:".time(); 
echo "<br>"; 

date_default_timezone_set("Europe/Helsinki"); 
echo "Europe/Helsinki:".time(); 
echo "<br>"; 
?> 

Local time as string can be get by strftime() and local timestamp (if ever needed) by mktime().