A javascript snippet to see how long a script or import is taking, will count when executed in your browser console

timer.js

var start = Date.now();
function output(variable){console.log(variable);}
setInterval(function() {
    var delta = Date.now() - start; // milliseconds elapsed since start
    output(Math.floor(delta / 1000)); // in seconds
    // alternatively just show wall clock time:
    output(new Date().toUTCString());
}, 1000); // update about every second