How are you going to fire off or schedule a check on crond ( the cron daemon) if it is not running? at, batch, and crontab all depend on the crond process being up, happy, and working.

A possibility is to look thru the process list every hour with a permanently running process. This is not a great idea but you could try something like this:

while true
do
   sleep 3600   # one hour
   ps -ef > /tmp/t.lis
   grep -q 'crond' /tmp/t.lis || echo 'crond is down' | /usr/bin/mailx -s 'crond is down'  me@my.com
done