js获取本日、本周、本月的时间代码

本日时间

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();   
}

昨天

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);     
 }
}

其他网友补充的完整测试代码

这样基本上就解决问题了