Cron notes & examples

1 minute (0-59)
2 hour (0-23)
3 day of month (1-31)
4 month (1-12, or name such as jan, feb, etc)
5 day of week ( 0-6 (6 = Sunday) or name such as mon, tue,etc)
6 command to run

MAILTO=myemailaddress@example.com
every 10 minutes
*/10 * * * * /home/user/cmd.sh

every hour @ XX:59
59 * * * * /home/user/cmd.sh

every 3rd hr @ XX:59
59 */3 * * * /home/user/cmd.sh

everyday @ 4:59am
59 4 * * * /home/user/cmd.sh

every saturday @ 4:59am
59 4 * * 5 /home/user/cmd.sh

weekdays hourly from 9-5
59 09-17 * * 1-5 /home/user/cmd.sh

first of every month @4:59 am
59 4 1 * * /home/user/cmd.sh

first wednesday of every month @4:59 am
59 04 1-7 * 2 /home/user/cmd.sh

on reboot
@reboot /home/user/cmd.sh