By default all accounts will have their .php files handled by PHP 5.2, if you wish a file to be handled by PHP 5.3 you simply need to change the extension of the file to .php53. For example:
index.php will be handled by PHP 5.2
index.php53 will be handled by PHP 5.3
If you would prefer for all of your .php scripts to be handled by PHP 5.3, there are two methods:
The quickest way to enable this is to simply open your ".htaccess" file in your /public_html folder and add this line:
AddType application/x-httpd-php53 .php
The more user-friendly but time consuming method is to add this entry via your cPanel.
Log into your cPanel account.
Access the "Apache Handlers" option under the "Advanced" section.
On the "Apache Handlers" page enter the following information:
Handler: application/x-httpd-php53
Exention(s): php
If you need to access the CLI version of 5.3 for a cron job you can do so using the command "/usr/bin/php53".