I have used this code for age calculator and it works perfectly...
You put it in any html page of your web site.
<div align="center">
<table border="1">
<td bgcolor=#00fa9a>
<script>
window.console = window.console || function(t) {};
</script>
<script>
if (document.location.search.match(/type=embed/gi)) {
window.parent.postMessage("resize", "*");
}
</script>
<body translate="no">
<div id="container">
<img src="zoPoGm_data/wLfwA7MS68Zd2KedA1vCX6-zLqDIUSwBC3W4GzgJaZBOlw6mjj0DatL.png" alt="">
<form id="form" autocomplete="off">
<div>
<p align="center" bgcolor=#fd0ee4>
<strong>বয়স ক্যালকুলেটর </strong></p>
<h5><p style ="color:red" align="center">( জন্ম তারিখ লিখুন ইংরেজিতে ) </p></h5></div>
<label for="date"> জন্ম তারিখ :
<input type="text" maxlength="2" size="5" id="date" placeholder="Date" autocomplete="on" required="" value="">
<input type="text" maxlength="2" size="5" id="month" placeholder="Month" autocomplete="on" required="" value="">
<input type="text" maxlength="4" size="5" id="year" placeholder="Year" autocomplete="on" required="" value="">
</label>
<br>
<br>
<label for="date2">
আজকের তারিখ:
<input type="text" maxlength="2" size="4" id="date2" placeholder="Date" value="">
<input type="text" maxlength="2" size="4" id="month2" placeholder="Month" value="">
<input type="text" maxlength="4" size="4" id="year2" placeholder="Year" value="">
</label>
<br>
<br>
<p align="center">
<button id="calbtn">বয়স দেখুন</button>
</p>
<span id="age">বয়স : 0 বছর, </span> <br>
<span id="months"> 0 মাস, </span> <br>
<span id="days"> 1 দিন৷ </span>
</form>
</div>
<script id="rendered-js">
var form = document.getElementById("form"),
bdate = document.getElementById("date"),
bmonth = document.getElementById("month"),
byear = document.getElementById("year"),
date = document.getElementById("date2"),
month = document.getElementById("month2"),
year = document.getElementById("year2"),
age = document.getElementById("age"),
days = document.getElementById("days"),
months = document.getElementById("months"),
today = new Date();
year.value = today.getFullYear();
month.value = today.getMonth() + 1;
date.value = today.getDate();
form.addEventListener('submit', function (event) {
event.preventDefault();
var by = Number.parseFloat(byear.value),
bm = Number.parseFloat(bmonth.value),
bd = Number.parseFloat(bdate.value),
ty = Number.parseFloat(year.value),
tm = Number.parseFloat(month.value),
td = Number.parseFloat(date.value);
if (td < bd) {
days.innerHTML = td - bd + 30 + ' দিন';
tm = tm - 1;
} else {
days.innerHTML = td - bd + ' দিন৷';
}
if (tm < bm) {
months.innerHTML = tm - bm + 12 + ' মাস,';
ty = ty - 1;
} else {
months.innerHTML = tm - bm + ' মাস,';
}
age.innerHTML = "আজকে আপনার বয়স : "
+ (ty - by) + ' বছর,';
});
//# sourceURL=pen.js
</script>
</td>
</table>
</div>