Wait until while loop with request is finished

Question

I have a date rangepicker where I select two dates. Then I check via an API for each day in a while loop if it is a holiday. Unfortunately I can't get the right result. I only get 0. Where is the mistake?

function(start, end, label) {
            var from = new Date(start.format('YYYY-MM-DD'));
            var to = new Date(end.format('YYYY-MM-DD'));
            var loop = new Date(from);
            let days = 0;
            while (loop <= to) {
                let day = ("0" + loop.getDate()).slice(-2);
                let month = ("0" + (loop.getMonth() + 1)).slice(-2);
                let myday = (day) + "." + (month) + "." + loop.getFullYear();
                $.get("https://ipty.de/feiertag/api.php", {
                    'do': "isFeiertag",
                    'datum': myday,
                    'loc': "BW"
                }).done(function(data) {
                    if ('0' == data) {
                        days++;
                    }
                });
                var newDate = loop.setDate(loop.getDate() + 1);
                loop = new Date(newDate);
            }
            console.log(days);
        }

Answer 1

I would probably advise you to execute the ajax calls inside Promises, and then use Promise.all to manage the outcomes.