please Help urgent

Question

hello guys I have a video & I need to invoke this function with PHP or Js
var myVar = document.getELementByID("myvideo");
//I need to built this function with PHP ||JS
function myfunc()
{ if (myVar start playing at 0 secand and stille onplay at 20 sec ) document.write ("hello world");
}

Answer 1

use date function, take two variables, one gets updated when the video starts and second gets updated +20 seconds when the video starts, and when the video reaches second variable, you output hello world.