Would it be enough to change /etc/cron.d/backup?
0 14 * * * root /bin/mt -f /dev/nst0 tell > /dev/null 2>&1 || echo "Remember to$
0 21 * * * root /sbin/e-smith/do_backup
to
0 14 * * 5 root /bin/mt -f /dev/nst0 tell > /dev/null 2>&1 || echo "Remember to$
0 21 * * 7 root /sbin/e-smith/do_backup
Is there any command to be run after saving changes in the file to reload the cronjob?