can you use a delay of less than a second on header("refresh:...") with PHP?

Question

I know you can refresh the page instantly in PHP using header("refresh: 0;");

You can also put your own delay, i.e. 3 seconds like this header("refresh: 3;");

My question is, is it possible to put a delay of less than one second, i.e. one tenth of second? header("refresh: 0.1;");

Answer 1

Tried it and it works

For example: header("refresh: 0.25;"); header("refresh: 0.1;"); header("refresh: 0.75;"); header("refresh: 0.5;"); all seem to work.