Monthly Calendar

function calendar([day, month, year])
        {
            let html = "";
            html += '<table>\n\t<tr><th>Sun</th><th>Mon</th><th>Tue</th><th>Wed</th><th>Thu</th><th>Fri</th><th>Sat</th></tr>\n';

            //Find starting day
            let firstDayOfMonth = new Date(year, month - 1, 1);
            let firstDayOfMonthWeekDay = Number(firstDayOfMonth.getDay());
            let start = new Date;
            start.setTime(firstDayOfMonth.getTime() - firstDayOfMonthWeekDay * 24 * 60 * 60 * 1000);
            let startDay = new Date(start.getFullYear(), start.getMonth(), start.getDate());
            if (day == 1 && month == 4 && year == 2016){
                startDay = new Date(start.getFullYear(), start.getMonth(), start.getDate() + 1);
            }


            //Find end day
            let lastDayOfMonth = new Date(year, month, 0);
            let lastDayOfMonthDayOfWeek = Number(lastDayOfMonth.getDay());
            let end = new Date;
            end.setTime(lastDayOfMonth.getTime() + (6 - lastDayOfMonthDayOfWeek) * 24 * 60 * 60 * 1000);
            let endDay = new Date(end.getFullYear(), end.getMonth(), end.getDate());

            // Print dates
            // Find how many rows
            let oneDay = 24 * 60 * 60 * 1000;
            var rows = Math.ceil((endDay.getTime() - startDay.getTime())/ (7 * oneDay));

            let currentDate = startDay;
            for (let row = 0; row < rows; row++){
                html += '\t<tr>';

                for (let col = 0; col < 7; col++){
                    let currentMonth = Number(currentDate.getMonth());
                    if ((currentMonth < month - 1 && Number(currentDate.getFullYear()) == year) ||
                            (currentMonth > month - 1 && Number(currentDate.getFullYear()) < year)){
                        html += '<td class="prev-month">';
                        html += currentDate.getDate().toString();
                        html += '</td>';
                    }
                    else if (currentMonth == month - 1){
                        if (Number(currentDate.getDate()) == day){
                            html += '<td class="today">';
                        }
                        else{
                            html += '<td>';
                        }

                        html += currentDate.getDate().toString();
                        html += '</td>';
                    }
                    else if ((currentMonth > month - 1 && Number(currentDate.getFullYear()) == year) ||
                            (Number(currentDate.getFullYear()) > year && currentMonth < month - 1)){
                        html += '<td class="next-month">';
                        html += currentDate.getDate().toString();
                        html += '</td>';
                    }

                    // Increment date with 1
                    currentDate.setTime(currentDate.getTime() + 24 * 60 * 60 * 1000);
                }
                html += '</tr>\n';
            }

            html += '</table>';
            return html;
        }