If you're just getting warnings about the timezone needing to be set, you can create (or add to) your /home/ACCOUNTNAME/public_html/php.ini file the line
date.timezone = 'America/New_York'
or whatever your proper timezone is (see the list: http://us3.php.net/manual/en/timezones.php
). If you're creating a php.ini file for the first time, you will probably have to add to your /.htaccess file:
where you use your real ACCOUNT NAME.
If you are getting other
warnings about deprecated functions, the best course would be to update your Joomla to the current version. You must be running a very old one not to be PHP 5.3 compliant. It's possible to fix it yourself, but beyond deprecated functions (http://us.php.net/manual/en/migration53.deprecated.php
) there are a number of other things that could require some major rewrites.
Note that I'm assuming you're on a Linux system. If you're on Windows, the fixes are probably different.