HTML and PHP

I ran the following code with the W3C online "PHP Tryit" editor.
<!DOCTYPE html>
<html>
<body>

<?php echo "Current London date and time";?>
<br>
<?php echo date("Y-m-d, H:i:s"); ?>
</body>
</html>
And got out
Current London date and time
2024-02-17, 05:28:02

But the Nu Html Checker (v.Nu) Saw <?. Probable cause: Attempt to use an XML processing instruction in HTML. (XML processing instructions are not supported in HTML.)

When I added it to one of my web pages it didn't run.

Why does it work one place but not another?

Received on Saturday, 17 February 2024 07:37:49 UTC