I don't know if exist a solution for enable a notify about events of the day imported in akonadi configuration.
Actually i have only the Plasmoid events but a notify it's very useful.
Everyone have an ideas?

Events such as reminders, calendars, to-dos? IIRC the way it works requires a reminder to be set. Or are you meaning a different type of event?

yes i refer to a reminder of the events

You can explicitly set a reminder of events for each of them in the event creation dialog. This will pop up a window when the reminder timer is fired.

I use owncloud for the events and i create the events in the web interface.

If you set a reminder in ownCloud, it should be picked up by KOrganizer once it syncs with your ownCloud server.