How to run script automatically every 12 hour once?

Hi ! all, I have once script to remove temporary cache and temporary xml files

looks like this, as it is taking more space, I would like to run automatically every 12 hour once, and then I want to receive some log as acknowledgement

#!/bin/sh
echo "Removing logs and temp files (typically done before starting tomcat)..."
JAVA_HOME="/usr/lib/jvm/jdk1.7.0_11"
JAVA_OPTS="-Djava.awt.headless=true -Xmx256M -Xms256M"
CATALINA_PID="/usr/local/www/html/TOMCAT_DEMO/tomcat/webapps/UI_PID"
CATALINA_HOME="/usr/local/www/html/TOMCAT_DEMO/tomcat"
export JAVA_HOME JAVA_OPTS CLASSPATH CATALINA_PID CATALINA_HOME
rm -rf $CATALINA_HOME/work/Catalina/localhost
rm -rf $CATALINA_HOME/logs/*
rm -rf $CATALINA_HOME/content/thredds/logs/*
rm -rf $CATALINA_HOME/content/ras/conf/server/temp/*
rm -rf $CATALINA_HOME/webapps/ras/output/*.*
find $CATALINA_HOME/content/ras/conf/server/data -type f -exec rm \{} \;
#cp /home/weusijana/RAS_custom_scripts/*.jnl $CATALINA_HOME/content/ras/conf/server/data/scripts
#exec $CATALINA_HOME/bin/catalina.sh start
echo "Done. You can now start tomcat."

please anyone tell me how it can be done.

If by "every 12 hours once" you mean once every 12 hours, you can run it via cron:

0 0,12 * * * /path/to/your/script

If you don't discard the output in the script, or in the cronjob, you should receive an email with the output. For more output, perhaps you want to use rm's -v option, depending on how many files you expect to be removed.

You may have to source .profile in the cronjob or in the script.

Thank you Sir, it requires root password, what I need to do more ?

Nothing in your script requires root password. You mean the script has to be run as root?

If that's the case, then the cronjob should be installed as root. Are those files not owned by the tomcat user?

no sir..I had not created tomcat user...infact..till date running script as a root user...thank you for your help...if I have any difficulty I will interrupt you once again sir...