利用js 获取本日 本周 本月时间代码

function showToDay()
{
    var Nowdate=new Date();
    M=Number(Nowdate.getMonth())+1
    alert(Nowdate.getMonth()+"月,"+Nowdate.getDate()+"号,星期"+Nowdate.getDay());
    return Nowdate.getYear()+"-"+M+"-"+Nowdate.getDate();
}

function showTomorrow()
{
    var tom=new Date();
    tom.setDate(tom.getDate()+1);
    M=Number(tom.getMonth())+1
    return tom.getYear()+"-"+M+"-"+tom.getDate();
}

本周第一天

function showWeekFirstDay()
{
    var Nowdate=new Date();
    var WeekFirstDay=new Date(Nowdate-(Nowdate.getDay()-1)*86400000);
    M=Number(WeekFirstDay.getMonth())+1
    return WeekFirstDay.getYear()+"-"+M+"-"+WeekFirstDay.getDate();
}

本周最后天

function showWeekLastDay()
{
    var Nowdate=new Date();
    var WeekFirstDay=new Date(Nowdate-(Nowdate.getDay()-1)*86400000);
    var WeekLastDay=new Date((WeekFirstDay/1000+6*86400)*1000);
    M=Number(WeekLastDay.getMonth())+1
    return WeekLastDay.getYear()+"-"+M+"-"+WeekLastDay.getDate();
}

本月第一天

function showMonthFirstDay()
{
    var Nowdate=new Date();
    var MonthFirstDay=new Date(Nowdate.getYear(),Nowdate.getMonth(),1);
    M=Number(MonthFirstDay.getMonth())+1
    return MonthFirstDay.getYear()+"-"+M+"-"+MonthFirstDay.getDate();
}

本月最后一天

function showMonthLastDay()
{
    var Nowdate=new Date();
    var MonthNextFirstDay=new Date(Nowdate.getYear(),Nowdate.getMonth()+1,1);
    var MonthLastDay=new Date(MonthNextFirstDay-86400000);
    M=Number(MonthLastDay.getMonth())+1
    return MonthLastDay.getYear()+"-"+M+"-"+MonthLastDay.getDate();
}

function getTime(s)
{
    var time1=document.getElementById("num1");
    var time2=document.getElementById("num2");
    if(s==1){
        //本日时间
        time1.value=showToDay();
        //alert("今日:"+time1.value);
        time2.value=showTomorrow();
        //alert("今日:"+time2.value);
    }else if(s==2){
        //本周时间
        time1.value=showWeekFirstDay();
        //alert("本月第一天:"+time1.value);
        time2.value=showWeekLastDay();
        //alert("本月最后一天:"+time2.value);
    }else{
        //本月时间
        time1.value=showMonthFirstDay();
        //alert("本月第一天"+time1.value);
        time2.value=showMonthLastDay();
        //alert("本月最后一天"+time2.value);
    }
}