I followed instructions from this website: http://colorblindprogramming.com/cronjobs-in-cakephp-2-in-5-steps , but my cronjob does not work.
This is my /app/cron_dispatc
Ignore that page, it gives false advice and proposes a bad architecture. It's just wrong.
Instead you should use a shell for that. See the page in the CakePHP book about shells.
Your application, if properly written, should have all data processing and manipulation code inside a model. By this the code is very easy to share between a controller and a shell.