根据日期获取周几

//根据日期获取周几

function getMyDay(date) {

    var week;

    if (date.getDay() == 0) week = "周日"

    if (date.getDay() == 1) week = "周一"

    if (date.getDay() == 2) week = "周二"

    if (date.getDay() == 3) week = "周三"

    if (date.getDay() == 4) week = "周四"

    if (date.getDay() == 5) week = "周五"

    if (date.getDay() == 6) week = "周六"

    return week;
}

var weekDay1 = getMyDay(new Date(“2017-9-15”));

对日期格式化后，算出周几

//对日期进行截取2017-7-9，返回9.15

function setMyDateFormate(date) {

    var formatDate = new Date(date);

    var MM = formatDate.getMonth() + 1;    

    var dd = formatDate.getDate();    

    var setDate = MM + "." + dd;

    return setDate;

}

//根据今天的日期，得到前后一段时期

function GetDateStr(AddDayCount) {

    var dd = new Date();

    dd.setDate(dd.getDate() + AddDayCount);//获取AddDayCount天后的日期 

    var y = dd.getFullYear();

    var m = dd.getMonth() + 1;//获取当前月份的日期 

    var d = dd.getDate();

    return y + "-" + m + "-" + d;

}