Создать динамический простой календарь на месяц

var today = new Date();
 
function createCalendar() {
    var calendar = document.createElement('div');
    calendar.id = 'calendar';
    var todayDate = today.getDate();
 
 
    var maxDays = 30;
    for (var i = 1; i <= maxDays; i++) {
        var dayTag = createDayTag(i);
        if (i === todayDate) {
            dayTag.classList.add('today')
        }
        calendar.append(dayTag)
        calendar.prepend(showMonth);
    }
 
    document.body.append(calendar);
}
 
function createDayTag(day) {
    var span = document.createElement('span');
    span.classList.add('day');
    span.textContent = day;
    return span;
}
 
 
function showMonth(today) {
    var months = ['January','February','March','April','May','June','July','August','September','October','November','December'];
    var currentMonth = months[today.getMonth()];
    return currentMonth;
}
showMonth(today);
 
function createMonthTag(currentMonth) {
    var month = document.createElement('span');
    span.classList.add('currentMonth');
    month.textContent = currentMonth;
    return month;
}