获取一周内，一月内，一年内的开始时间和结束时间

// 时间格式
function formatDate(now)   { 
    var now=new Date(now);    
    var year=now.getFullYear();     
    var month=now.getMonth()+1;     
    var date=now.getDate();     
    var hour=now.getHours();     
    var minute=now.getMinutes();     
    var second=now.getSeconds();     
    return   year+"-"+addZero(month)+"-"+addZero(date)+" "+addZero(hour)+":"+addZero(minute)+":"+addZero(second);     
     
//时间范围
function durTime(param){
    var date = new Date()*1;
    var timeStr = {};
    //开始时间
    timeStr.startTime = formatDate(date);
    if(param == "day"){
        var endStr = date-24*60*60*1000;
        timeStr.endTime = formatDate(endStr);
    }else if(param == "week"){
        var endStr = date-7*24*60*60*1000;
        timeStr.endTime = formatDate(endStr);
    }else if(param == "month"){
        var endStr = date-30*24*60*60*1000;
        timeStr.endTime = formatDate(endStr);
    }else if(param == "year"){
        var endStr = date-365*24*60*60*1000;
        timeStr.endTime = formatDate(endStr);
    }
    return timeStr
}
// 补零
function addZero(val){
    if(val>=10){
        return val;
    }else{
        return "0"+val;
    }
}
// 调用
console.log( durTime("day") );
console.log( durTime("week") );
console.log( durTime("month") );
console.log( durTime("year") );