CentOS 怎样安装crontab

crontab -e 发现没有这个命令， 怎样安装？ 试了下yum install crontab 也没有。

-bash: crontab: command not found
yum install crontab
Loaded plugins: fastestmirror
Setting up Install Process
Loading mirror speeds from cached hostfile
 * webtatic: uk.repo.webtatic.com
No package crontab available.