Same events every year

Hi!

I bought your plugin, but I need some modification for it.

How can I make that when I add a event, its visible for every year not only for one date.

And I’am trying to make that when I press next button for calendar, it turn not only for a month, but whole year.

changeDay(‘prev’,timestamp, $instance);

I guess I have to change here something? Maybe someone have done this and could give me some tips how to create this?

https://www.ads-software.com/plugins/wp-simple-booking-calendar/