How do I deny / allow access to cron in Linux

[petulia3478]

To deny a user access to cron, add the user name to /etc/cron.deny, as root. If the file doesn't exist, create it.

To allow a user access to cron, add the user name to /etc/cron.allow, as root. If the file doesn't exist, create it.

Enter one user name per line. No spaces.

If /etc/cron.allow exists, users listed in that file are allowed to use cron and /etc/cron.deny is ignored.
If /etc/cron.allow doesn't exist, users listed in /etc/cron.deny are not allowed to use the cron facility.

It is not necessary to restart cron after modifying /etc/cron.deny or /etc/cron.allow