try
--------------------------------------------
<input type="text" id="text1" value="2005-12-9">
<input type="text" id="text2">
<input type="button" onclick="getDate();" value="show"><script language="javascript">
function getDate(){
var arr = document.getElementById("text1").value.split("-");
var d = new Date(arr[0] + "/" + (arr[1] * 1 +3) + "-10");
document.getElementById("text2").value=d.getFullYear() + "-" + d.getMonth() + "-10";
}
</script>
--------------------------------------------
<input type="text" id="text1" value="2005-12-9">
<input type="text" id="text2">
<input type="button" onclick="getDate();" value="show"><script language="javascript">
function getDate(){
var arr = document.getElementById("text1").value.split("-");
var d = new Date(arr[0] + "/" + (arr[1] * 1 +3) + "-10");
document.getElementById("text2").value=d.getFullYear() + "-" + d.getMonth() + "-10";
}
</script>
那个日期默认是月份和天数都是两个字符,年份为一个字符:mmmm-yy-tt
而且加的只是2没有加3
<HTML>
<HEAD>
<TITLE> New Document </TITLE>
<script>
function changeDate(){
var obj=document.getElementById("text1").value;
var dayPos=obj.lastIndexOf("-");
var yearPos=obj.indexOf("-");
year=obj.substring(0,yearPos);
var month=obj.substring(yearPos+1,dayPos-1);
if(month!="0"){
month=obj.substring(yearPos+1,dayPos);
}
else{
month=obj.substring(yearPos+2,dayPos);
}
month=parseInt(month)+3;
if(month>12){
month="0"+(month-12).toString();
year=year+1;
}
day="10";
var newDate=year+"-"+month+"-"+day;
document.getElementById("text2").value=newDate;
}
</script>
</HEAD><BODY>
<input type="text" id="text1" value="1980-08-07">
<input type="button" value="改变时间" onclick="changeDate()" >
<input type="text" id="text2">
</BODY>
</HTML>
--------------------------------------------------
<input type="text" id="text1" value="2005-12-9">
<input type="text" id="text2">
<input type="button" onclick="getDate();" value="show"><script language="javascript">
function getDate(){
var arr = document.getElementById("text1").value.split("-");
var d = new Date(arr[0] + "/" + (arr[1] * 1 +4) + "-10");
document.getElementById("text2").value=d.getFullYear() + "-" + (d.getMonth().toString().length<2?"0"+d.getMonth():d.getMonth()) + "-10";
}
</script>
<HEAD>
<TITLE> New Document </TITLE>
<script>
function changeDate(){
var obj=document.getElementById("text1").value;
var dayPos=obj.lastIndexOf("-");
var yearPos=obj.indexOf("-");
year=obj.substring(0,yearPos);
var month=obj.substring(yearPos+1,dayPos-1);
if(month!="0"){
month=obj.substring(yearPos+1,dayPos);
}
else{
month=obj.substring(yearPos+2,dayPos);
}
month=parseInt(month)+3;
if(month>12){
month="0"+(month-12).toString();
year=year+1;
}else if(month<10){
month="0"+month.toString();
}
day="10";
var newDate=year+"-"+month+"-"+day;
document.getElementById("text2").value=newDate;
}
</script>
</HEAD><BODY>
<input type="text" id="text1" value="1980-08-07">
<input type="button" value="改变时间" onclick="changeDate()" >
<input type="text" id="text2">
</BODY>
</HTML>