Cron Job Not Running?

Add a >>/tmp/testlog.log to the end of your crontab entry (to redirect output to a file you can investigate or check if it's running, additionally a 2>&1 would include output from the error console)

Example

0 * * * * /home/abliskovs/update/update.sh 2>&1 /tmp/testlog.log

Also Make Sure the followings :

• Add cronjobs in a right manner. if you've used crontab -e within your own account, scripts are run with your user (and thus the crontab entry has one field less -- the user to run it, as that is known). If you simply copied your above snipped to /etc/cron.d, it would fail as you didn't specify a user (or rather as it finds no user named "bash").
• Make sure that the script file is executable, otherwise it will not execute it.
• Reload the cron jobs sudo service reload, or restart cron service sudo /etc/init.d/cron restart

How to make a file executable?

Several ways to make your file executable

chmod +x /home/abliskovs/update/update.sh 

chmod -R 0755 /home/abliskovs/update/update.sh

chmod a+x /home/abliskovs/update/update.sh

Make sure that the script file is executable {chmod 755} otherwise it will not execute it