Look here: https://www.w3schools.com/js/js_dates.asp

There are many ways to do what you want. Jaca or PHP.

The example page delivers code you can copy and put into a html object.

The code can be edited as you wish.

Jaca >>> java

Thanks John

Could be something like this:

<div id="demo"></div>

<script>
const d = new Date();
document.getElementById("demo").innerHTML = d;
</script>

Beware that the date/time is "static" unless you make code to refresh it.

Maybe it is better to have only the date like this:

<div id="date"></div>

<script>
var date = (new Date()).toISOString().split('T')[0];
document.getElementById('date').innerHTML = date;
</script>