Hi,
I would like to use the calendar Calendar - Home Assistant in the Home Assistant and send notifications to all phones based on events in the calendar.
I would like to ask you where to create the calendar in Home Assistant?
I found various tutorials on how to link to HA a Google calendar. But I don’t need that.
I need a calendar directly in HA, where I mark events and do automation, which will send notifications based on events.
I am afraid that the calendar integration is not a “stand alone” calendar and that it always needs an external calendar of some kind.If you search for calendar in the integrations (in your HA) you’ll notice it only shows google calendar.
I think you can’t actually make one directly in HA and are always depended on linking it to an external calendar. There are more options however then just google calender. You could look into CalDav. Which allows you to integrate with other services (I use it to integrate with iCloud’s calenders for example).
There also is a HACS integration that allows you to use sensors as entries for a calendar. But that’s also not really what I think you are looking for unless it’s just repeatable events?
i would like to see even just a limited calendar for HA that was more native
Well, just be patient for 1 more day 
Shipped in yesterdays release
Anyone knows how to create an event on a caldav calendar?
Specifically a Nextcloud calendar?