js获取当前日期一年的第几周

获取当前日期一年中的第几周

    function theWeek() {
        var totalDays = 0;
        now = new Date();
        years = now.getYear()
        if (years < 1000)
            years += 1900
        var days = new Array(12);
        days[0] = 31;
        days[2] = 31;
        days[3] = 30;
        days[4] = 31;
        days[5] = 30;
        days[6] = 31;
        days[7] = 31;
        days[8] = 30;
        days[9] = 31;
        days[10] = 30;
        days[11] = 31;
        //判断是否为闰年，针对2月的天数进行计算
        if (Math.round(now.getYear() / 4) == now.getYear() / 4) {
            days[1] = 29
        } else {
            days[1] = 28
        }
        if (now.getMonth() == 0) {
            totalDays = totalDays + now.getDate();
        } else {
            var curMonth = now.getMonth();
            for (var count = 1; count <= curMonth; count++) {
                totalDays = totalDays + days[count - 1];
            }
            totalDays = totalDays + now.getDate();
        }
        //得到第几周
        var week = Math.round(totalDays / 7);
        return week;
    }