Introduction
You can adjust the PHP execution on your own, here are some methods to try. I recommend starting at the top an working your way down the list. Apply only one change at a time, do not try to apply them all.
Be aware that this requires advanced knowledge; it is not basic and you can crash your site. If you are not comfortable applying these changes it is highly suggested you contact your web host tech support for assistance.
The recommended limit is 300 seconds.
Increasing the Execution Limit via wp-config.php
Add this to the very bottom, right before the line that says, “Happy Blogging”:
set_time_limit(300);
You can learn more about this change in the WordPress documentation; Maximum Execution Time Exceeded.
Increase the Execution Limit via php.ini
Many shared hosting providers to not provide access to the the php.ini file. However, if your web host does provide access to the file, search for the line that begins with max_execution_time and change its value to 300. If it does not have this line, add this to the bottom of the file:
max_execution_time=300
You will have to consult your web host tech support documentation or contact them to determine if they provide access to this file.
Increase the Execution Limit via .htaccess file
On web hosts where you do not have access to the php.ini you might be able to adjust the execution limit using the .htaccess file. Add this line to the top of the file:
php_value max_execution_time 300
Important, if your host does not support setting PHP environmental values using the .htaccess file, adding this line could cause the server to return an error instead of loading your site. Removing this line will correct the error and allow the site to load.
Contact Your Web Host
If none of these methods work, please contact your web host support to help you increase the PHP execution limit.