HTML5实现签到 功能

//生成日期数据
    function buildData() {
        var da = {
            dates: [],//日期数据，从1号开始
            current: '',//当前日期
            monthFirst: 1,//获取当月的1日等于星期几
            month: 0,//当前月份
            days: 30,//当前月份共有多少天
            day: 0,//今天几号了
            isSigned: false,//今天是否已经签到
            signLastDays:3,//连续签到日子
            signToday: function () {
                this.isSigned = true;
                this.dates[this.day].isSigned = true;
            },
        };
        var ds = [];
        //初始化日期数据
        var dt = new Date();
        da.current = dt.ToString('yyyy年M月d日');
        da.monthFirst = new Date(dt.getFullYear(), dt.getMonth(), 1).getDay();
        da.month = dt.getMonth() + 1;
        da.days = new Date(dt.getFullYear(), parseInt(da.month), 0).getDate();//获取当前月的天数
        da.day = dt.getDate();
        for (var i = 1; i < da.days + 1; i++) {
            var o = {
                isSigned: false,//是否签到了
                num: i,//日期
                isToday: i == da.day,//是否今天
                isPass: i < da.day,//时间已过去
            };
            ds[i] = o;
        }
        da.dates = ds;
        return da;
    }

 //渲染数据
    function renderData(da) {
        var signDays = document.getElementById('spSignDays');
        signDays.innerText = da.signLastDays;
        var root = document.getElementById("signTable");
        root.innerHTML = '';
        var tr, td;
        var st = da.monthFirst;
        var dates = da.dates;
        var rowcount = 0;
        //最多6行
        for (var i = 0; i < 42; i++) {
            if (i % 7 == 0) {
                //如果没有日期了，中断
                if (i > (st + da.days))
                    break;
                tr = document.createElement('tr');
                tr.className = 'darkcolor trb';
                root.appendChild(tr);
                rowcount++;
            }
            //前面或后面的空白
            if (i < st || !dates[i - st + 1]) {
                td = document.createElement('td');
                td.innerHTML = '<div class="sign-blank"><span></span></div>';
                tr.appendChild(td);
                continue;
            }
            //填充数字部分
            var d = dates[i - st + 1];
            td = document.createElement('td');
            var tdcss = '';
            if (d.isToday)
                tdcss = 'sign-today';
            else if (d.isPass)
                tdcss = 'sign-pass';
            else
                tdcss = 'sign-future';
            if (d.isSigned) {
                tdcss = 'sign-signed ' + tdcss;
                td.innerHTML = '<div class="' + tdcss + '"><span>' + d.num + '</span><svg xmlns="http://.w3./2000/svg" version="1.1" class="sign-pin svg-triangle "><polygon points="0,0 35,0 0,35" /></svg></div>';
            } else {
                tdcss = 'sign-unsign ' + tdcss;
                td.innerHTML = '<div class="' + tdcss + '"><span>' + d.num + '</span></div>';
            }
            tr.appendChild(td);
        }
        //计算是否需要添加一行
        if ((st + da.days + 1) / 7 > rowcount)
            root.appendChild(tr);
    }
       //构建日期数据
        var da = buildData();
        //渲染
        renderData(da);