How to implement two pop-up banners so that they pop up once per session (at 12 o'clock) in turn?

Question

PHP

The site has a popup banner that is displayed every 12 hours
const banner = $('.popup-banner');
let bannerName = banner.attr('cookie-data');
if (!$.cookie(bannerName)) {
setTimeout(function() {
$(".popup-shadow").fadeIn(200);
banner.addClass('popup-opened');
banner.fadeIn(300);
}, 5000);
}
$(".popup-banner a").click(function() {
let cookieName = $(this).parents('.popup-banner').attr('cookie-data');
var date = new Date ();
var hours = 12;
date.setTime(date.getTime() + (hours * 60 * 60 * 1000));
$.cookie(cookieName, true, {
expires: date,
path: '/'
});
});
but you need to make two such banners so that they are displayed either once every 12 hours or once per session in a checkerboard pattern (in turn), i.e. first session banner 1 second banner 2 third banner 1 etc. ? With what can this be done?

Answer 1

once per session

Use PHP session
Cookie or saving to the database (if the user is logged in)
PS In general, all pop-up banners are blocked by default by browsers. Last resort plugins. So it's better to do at least something useful for the site.