How to set cron job which runs every month?

After logging in, click on “Add new cron job”, enter a cron job name (optional), choose following configurations in time setting dropdown boxes:
Minute: any number from 0 to 59
Hour: any number from 0 to 23
Day: any number from 1 to 28 (These dates will be always safe for all months including Feb)
Month: *
Weekday: *

Enter the URL you want to call and choose the rest settings if necessary, click on “Create” button, wait until the notice popups, you're done.
The final time pattern will be "(the number you set for minute field) (the number you set for hour field) (the number you set for day field) * *" after the cron job is added.