设置一周从周一或者周日开始？

now = new Date();
weekVal = now.getDay();

        if (weekVal==0)
        msg1="星期日";
    else if (weekVal==1)
        msg1="星期一";
    else if (weekVal==2)
        msg1="星期二";
    else if (weekVal==3)
        msg1="星期三";
    else if (weekVal==4)
        msg1="星期四";
    else if (weekVal==5)
        msg1="星期五";
    else if (weekVal==6)
        msg1="星期六";
看看试不是这样！