cron script generating errors. possibly taking down the site.

Im not sure where this falls under so I hope I assigned it to the correct zone, heres the issue:

We have a dedicated server running a fully custom site that relies on several scripts that are used to update the site and deliver content (the site is fully automated) lately we've run into an issue where at a specific time every night, it seems to go down (system becomes unresponsive, etc)

the only error we can find is from one of the cron jobs that run:

this is the error:
/root/servrs/freezerestart.sh: line 5: ((: 059: value too great for base (error token is "059")
/root/servrs/freezerestart.sh: line 5: ((: 059: value too great for base (error token is "059")

it goes up from 009 up to that last one, then seems to crash.

here is the script: (the site has been omitted with ------)

can someone look at the script and let me know, if anything would be generating the error ?

the purpose of the script is if the site becomes unresponsive, it forces a restart of the site,
which is fine, but more often than not it never runs and the rig grinds to a halt, at exactly 5am est.


#!/bin/sh

tm=$(date +%k%M)

if (( $tm < 500 )) || (( $tm > 530 )) ; then

    curdate=$(date)
    okfname=$(date +%F)
    freeze=$(/usr/bin/perl /root/servrs/socktest.pl)
    wst=$(/usr/bin/curl --connect-timeout 15 -s --head "http://---------.org" | /usr/bin/perl -e 'my ($a) = <STDIN>; print $a = (split /\s+/, $a)[1]*1')

    if (( $freeze == 1 )) || (( $wst == 500 )) || (( $wst == 0 )); then

        pids=$(/usr/sbin/lsof /tmp/site.socket | /usr/bin/perl -e 'my @pids = map {((split /\s+/, $_)[1])} (<STDIN>); $, = "\n", print @pids[1..$#pids]');

        su - siteuser -c "~/run_-----------_site"

        for i in $pids; do
                kill -9 $i
        done
      echo "Restarted because fail on $curdate" >> /root/servrs/fail_state
    else
        echo "OK and HTTP $wst on $curdate" >> /root/servrs/ok_state_$okfname
    fi
fi