Create task cron

Hello, I try to launch a cron task on Projeqtor v7.4.3, I have put my file.php under files/cron and I have also try putting my code in index.php of this folder, no error on log when I launch cron on administration but no result either. My code work, is there a place where I can found :

- where I must put my cron task

- where could I write delay command (like crontab :     0        2          12             *                *            /usr/bin/find)