Mark a calendar php mysql

Solution for Mark a calendar php mysql
is Given Below:

I have an open source web app about vaccination scheduler. People who want to get vaccinated click the date and fill in the form until certain quota. The date available monday to friday. saturday and sunday off.
My question is how to make a certain date to be off because its a holiday (no vaccination available)?
I am thinking about mark the certain date as a holiday. so, whenever it get to marked date, the date would be not available. But i dont now how to set it.

Here is the code about it:

var calendar = new Calendar(calendarEl, {
             headerToolbar: {
                 left: 'prev,next today',
                 center: 'title',
                 right: false
             themeSystem: 'bootstrap',
             //Random default events
             events: function(event, successCallback) {
                 var days = moment(event.end).diff(moment(event.start), 'days')
                 var events = []
                 for ($i = 0; $i < days; $i++) {
                     if ($i == 0)
                         date = moment(event.start);
                         date = moment(event.start).add($i, 'days')
                     avail = !scheds[moment(date).format("YYYY-MM-DD")] ? max : max - parseInt(scheds[moment(date).format("YYYY-MM-DD")]);
                     // console.log(moment().subtract(1, 'day').diff(date))
                     if (moment().subtract(1, 'day').diff(date) < 0 && (moment(date).format('dddd') != 'Saturday' && moment(date).format('dddd') != 'Sunday') && avail > 0) {
                             title: 'Available: ' + avail,
                             start: moment(date).format("YYYY-MM-DD"),
                             backgroundColor: 'var(--primary)', //red
                             borderColor: 'var(--light)', //red
                             allDay: true


             eventClick: function(info) {
                 date = moment(info.event.start).format("YYYY-MM-DD");
                 uni_modal("", "./addSchedule.php?lid=<?php echo $lid ?>&d=" + date, "large")
             selectable: true,
             selectAllow: function(select) {
                 // console.log(moment(select.start).format('dddd'))
                 if (moment().subtract(1, 'day').diff(select.start) < 0 && (moment(select.start).format('dddd') != 'Saturday' && moment(select.start).format('dddd') != 'Sunday'))
                     return true;
                     return false;