YouTube Playlist Time

Adds a timestamp of all videos' time combined.

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(I already have a user script manager, let me install it!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name        YouTube Playlist Time
// @namespace   YouTube Playlist Time
// @description Adds a timestamp of all videos' time combined.
// @author      kriscross07
// @include     *.youtube.com/*
// @version     1.6
// @grant       none
// @run-at      document-start
// ==/UserScript==

addEventListener('DOMContentLoaded',function(){
  var time,mins=0,interval=true;

  addControls();
  interval&&setInterval(addControls,100);
  
  function addControls(){
    if(time&&document.contains(time)||!/^https:\/\/www.youtube.com\/playlist/.test(location.href))return;
    
    time=document.createElement('span');
    
    time.onclick=updateTime;
    time.title=time.innerHTML='Click to update time.';
    
    document.querySelector('.playlist-actions').appendChild(time);
    updateTime();
  }
  function updateTime(){
    var stamps=document.querySelectorAll('.timestamp>span');
    mins=0;
    for(var i=0;i<stamps.length;i++){
      var min=stamps[i].innerHTML.split(':');
      mins+=min[1]>=30?parseInt(min[0])+1:parseInt(min[0]);
    }
    time.innerHTML=mins>60?(mins/60).toFixed(1)+' hours.':mins+' minutes.';
  }
});