Zabbix history max value 2

#!/bin/bash

start_daytime=$(date --date "$1 00:00:00" +%s)
end_daytime=$(date --date "$2 00:00:00" +%s)
itemid=${3:-23347}

sql_string="select history.itemid, items.name, history.clock, history.value \
   from history INNER JOIN items ON history.itemid=items.itemid \
   where value = ( select max(value) from history where itemid=$itemid and \
   clock >= $start_daytime and clock <= $end_daytime) \
   and history.itemid=$itemid and history.clock >= $start_daytime \
   and history.clock <= $end_daytime\G"

for f in $(mysql -B -s -r -u root -p zabbix -e "$sql_string" | sed -e '/^\*.*\*$/d' -e 's/ //g')
do
   if [ ${f%:*} = "clock" ]; then
      date_str=$(date --date @${f##*:})
      echo ${f%:*}:${date_str}
   else
      echo $f
   fi
done