Sleep function php

Hi everyone,

I was wondering if the sleep function when used consume much processing power or is it a bad practice to use it as i want a function to kick in every day at a certain time and then sleep and wait untill the next day?

e.g. function runs and check the DB to see whether or not it must update / delete data. So function for e.g. runs everyday at 00:00 and sleep until it must run again.

Please does anybody can put me on the right track.


Jerome Chevreau