let selected_weekdays = {% autoescape off %} {{ selected_weekdays }} {% endautoescape %}
        if (selected_weekdays !== {}){
            defaultCheckedCheckboxDate(selected_weekdays)
            let elements = document.getElementsByClassName(`week_day`);
            for (let key in selected_weekdays) {
                for (let i = 0; i < elements.length; i += 1) {
                   if (elements[i].abbr === key ) {
                       elements[i].innerHTML = `<a href="{% url "date_by_student" date_day=1 mtb_id=id_month_timetable_tutor %}">${key}</a>`;
                       elements[i].style = "background: aquamarine";
                  }
                }
            }
        }