In some cases, the WHMCS software inexplicably uses wrong server timezone. Despite having configured php.ini, the WHMCS software reflects incorrect server time and causes mistimed automations (Daily Crons, Domain Sync, etc).
When this is the case. edit the configuration.php file in the root WHMCS installation, adding the following text to the end of the file:
Edit the timezone to the appropropriate desired timezone of your server. Save the file.
Your WHMCS timezone is now synchronized with the server clock.