Go to the home folder:

cd ~

Create a script called update_time.sh.

nano update_time.sh

Write this code inside:

sudo date -s "$(wget -qSO- --max-redirect=0 google.com 2>&1 | grep Date: | cut -d' ' -f5-8)Z"

Save it and exit by pressing Control+X and after Y.

Make the script executable:

chmod +x update_time.sh

Run crontab with the -e flag to edit the cron table:

crontab -e

The first time you run crontab you'll be prompted to select an editor; if you are not sure which one to use, choose nano by pressing Enter.

Write a cronjob to call the script every hour:

10 * * * *  /home/pi/update_time.sh

Save it and exit by pressing Control+X and after Y.

View your currently saved scheduled tasks with:

crontab -l