var mydateInputbeginDate = document.getElementById("beginDate");
var datebeginDate = new Date();
datebeginDate.setMonth(datebeginDate.getMonth()-1);
//下面语句判断，当月份小于10月时，前面位0
var YbeginDate = datebeginDate.getFullYear();
var MbeginDate = datebeginDate.getMonth() + 1;
if( MbeginDate < 10){
MbeginDate = '0' + MbeginDate;
}
var DbeginDate = datebeginDate.getDate();
if( DbeginDate < 10){
DbeginDate = '0' + DbeginDate;
}
var dateStringbeginDate = YbeginDate + "-" + MbeginDate + "-" + DbeginDate;
mydateInputbeginDate.value = dateStringbeginDate;
var mydateInput = document.getElementById("endDate");
var date = new Date();
//下面语句判断，当月份小于10月时，前面位0
var Y = date.getFullYear();
var M = date.getMonth() + 1;
if( M < 10){
M = '0' + M;
}
var D = date.getDate();
if( D < 10){
D = '0' + D;
}
var dateString = Y + "-" + M + "-" + D;
mydateInput.value = dateString;
参考
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
</head>
<body>
<input type="text" class="form-control input-medium" placeholder="开始时间" name="" id="startTime" />
<input type="text" class="form-control input-medium" placeholder="结束时间" name="" id="endTime" />
</body>
<script type="text/javascript">
var mydateInputbeginDate = document.getElementById("startTime");
var datebeginDate = new Date();
datebeginDate.setMonth(datebeginDate.getMonth()-1);
//下面语句判断，当月份小于10月时，前面位0
var YbeginDate = datebeginDate.getFullYear();
var MbeginDate = datebeginDate.getMonth() + 1;
if( MbeginDate < 10){
MbeginDate = '0' + MbeginDate;
}
var DbeginDate = datebeginDate.getDate();
if( DbeginDate < 10){
DbeginDate = '0' + DbeginDate;
}
var dateStringbeginDate = YbeginDate + "-" + MbeginDate + "-" + DbeginDate;
mydateInputbeginDate.value = dateStringbeginDate;
var mydateInput = document.getElementById("endTime");
var date = new Date();
//下面语句判断，当月份小于10月时，前面位0
var Y = date.getFullYear();
var M = date.getMonth() + 1;
if( M < 10){
M = '0' + M;
}
var D = date.getDate();
if( D < 10){
D = '0' + D;
}
var dateString = Y + "-" + M + "-" + D;
mydateInput.value = dateString;
</script>
</html>
