How do I navigate to hashtag after page load?

For some reason both MS Edge 42 and IE 11 will not scroll to the new bookmark for me, even when doing a window.location.reload(true) after setting the new bookmark. So I came up with this solution: insert this script on the page you're loading (requires jquery)

$(document).ready(function() {
 var hash = window.location.hash;
 if (hash) {
  var elem = document.getElementById(hash.substring(1));
  if (elem) {
   elem.scrollIntoView();
  }
 }
});

If you simply want to change the hash after page loads:

window.onload = function (event) {
    window.location.hash = "#my-new-hash";
};

If you want to navigate to the URL with new hash:

window.location.href = "http://website.com/#my-new-hash";

If you want to listen for changes in the hash of the URL; you can consider using the window.onhashchange DOM event.

window.onhashchange = function () {
    if (location.hash === "#expected-hash") {
        doSomething();
    }
};

But it is not supported by every major browser yet. It now has a wide browser support. You can also check for changes by polling the window.location.hash on small intervals, but this is not very efficient either.

For a cross-browser solution; I would suggest Ben Alman's jQuery hashchange plugin that combines these methods and a few others with a fallback mechanism.

EDIT: After your question update, I understand you want the page to scroll to a bookmark?:

You can use Element.scrollTop or jQuery's $.scrollTop() method.

$(document).ready(function (event) {
    var yOffset = $("#my-element").offset().top;
    $("body").scrollTop(yOffset);
});

See documentation here.