actual script

>>> cat ./petr.sh
#!/bin/bash

set -x
shopt -s lastpipe

NOW=$(date +%s)
TOLLERANCE=10800
TOLLERANCE=10
CNT=0

ps axuf | grep CRON | grep -v grep | \
while read -r line; do
        ID=$(echo $line | awk '{print $2}')
        CRON_TIMESTAMP=$(ls -ld --time-style=+%s /proc/$ID/ | awk '{print $6}')
        DIFF=$((NOW - CRON_TIMESTAMP))
        if [ $DIFF -gt $TOLLERANCE ]; then
                CNT=$(( CNT + 1 ))
        fi

done

echo $CNT