The max_execution_time directive defines the maximum execution time for your PHP scripts and applications. If not configured, the default maximum execution time for a PHP script is 30 seconds. PHP will timeout and exit with a fatal error once it reaches the time limit.

Fatal error: Maximum execution time of 30 seconds exceeded in yourscript.php

You can set PHP's time limit by configuring max_execution_time option so that your script won't timeout and exit with an error.

There are a few methods to set the option, such as configuring the php.ini file, using ini_set() and set_time_limit() functions, and using a .htaccess file. cPanel, on the other hand, allows setting up the max_execution_time option from the web interface.

This approach will affect all the PHP scripts running in your system. It's the best solution if you're running a content management system or framework like WordPress or Drupal as you don't need to configure the option manually to all the affected scripts.

Set the max_execution_time in your PHP configuration file to the number of seconds that want to allow your PHP scripts to execute.

1. Open php.ini file using your favourite text editor.

   $ sudo vi /etc/php/7.2/apache2/php.ini

   Related: PHP configuration files

2. Look for max_execution_time directive.

   ; Maximum execution time of each script, in seconds ; http://php.net/max-execution-time ; Note: This directive is hardcoded to 0 for the CLI SAPI max_execution_time = 30

3. Set the value for max_execution_time in seconds.

   max_execution_time = 300

   Setting it to 0 will impose no time limit whatsoever to the execution of your PHP scripts.

   It's not recommended to set the value to 0 at this level as this method's system-wide change will cause any misbehaved PHP scripts to unnecessarily consume precious CPU time.

4. Restart your web server.

   $ sudo systemctl restart apache2

   Related: How to manage Apache service

It is basically the same as the previous solution, but it's actually a function you call from your PHP script. It's a general function to override any configuration options set in your PHP's configuration file and only affect the execution of the scripts that call the function.

When placed at the start of your PHP script, the following function call will allow it to run for 300 seconds (5 minutes).

ini_set('max_execution_time', 300);

The function call should be placed in shared files such as the configuration files for CMS and frameworks. For WordPress it's wp-settings.php.

It is a PHP built-in function specifically to set the maximum execution time limit of your PHP scripts. It's to be called from your PHP script as in the previous method, and the following example is to also set the limit to 300 seconds (5 minutes).

set_time_limit ( 300 );

This is the best option if you don't have administrator access to your system but still want to set the option to all your scripts in your project folder.

Add the following lines to .htaccess file within your PHP project folder, and this will be applied to all the scripts within that folder.

<IfModule mod_php7.c> php_value max_execution_time 300 </IfModule>

The option is readily available in cPanel's dashboard and can be used to change PHP's maximum execution time limit.