cron jobs not working

First let me explain there are no error logs or even email notifications stating the cron job has even tried to execute.


Cron Job:

php /home/<private>/public_html/cron_day.php 12345678910123456789


The numbers at the end represent an alnum security code to keep it from being used outside of it's means.


Like I said, no error reports period just that the crons are not working. If I enter 12345678910123456789 into my url bar I get a 404 error. (Would explain the lack of an error log). But typing works fine.


Thing is without any error logs how am I suppose to know what is wrong??