Cron every 5 minutes

You’ll need to add a new schedule for this from the Settings -> Cron Schedules screen, then you can use that schedule when you edit a cron event.

That said, an event with such a short interval may not be reliable, depending on how much traffic your website gets. More info here: https://github.com/johnbillion/wp-crontrol/wiki/Cron-events-that-have-missed-their-schedule .

Thanks i need short interval because the purpose of my CRON is for Ical calendar availability sync purpose https://help.wprentals.org/article/icalendar-feed-cron/

I think that with 5 minutes CRON i can reduce a lot the risk of overbooking. What do you think?