Are you looking for crontab on a new install of CentOS 5? Well if you do a custom installation and don’t select anything then it will not be installed by default. In order to install it there just needs to be one package installed. See the below commands to install and setup crontab.
Use this command to install crontab, start the cron daemon, and turn it on at startup.
yum install vixie-cron crontabs /sbin/chkconfig crond on /sbin/service crond start
To edit crontab entries use the following command which will open up the crontab editor in vi the default text editor.
set default editor for crontab