approve_time_ago.user.js

// ==UserScript==
// @name        Approve time ago
// @author      Enigma
// @namespace   reddit_approve_time_ago
// @include     /^https?://(.+\.)?reddit.com\//
// @version     1
// @grant       none
// ==/UserScript==

($(function() {
  function s(t) {
    if(t != 1) {
      return "s";
    }
    return "";
  }
  
  function timeAgoStr(t) {
    var seconds = t/1000;
    var minutes = seconds/60;
    var hours = minutes/60;
    var days = hours/24;
    var years = days/365;
    
    if(seconds < 60) {
      var v = Math.floor(seconds);
      return v+" second"+s(v)+" ago";
    }
    else if(minutes < 60) {
      var v = Math.floor(minutes);
      return v+" minute"+s(v)+" ago";
    }
    else if(hours < 24) {
      var v = Math.floor(hours);
      return v+" hour"+s(v)+" ago";
    }
    else if(days < 365) {
      var v = Math.floor(days);
      return v+" day"+s(v)+" ago";
    }
    else {
      var v = Math.floor(years);
      return v+" year"+s(v)+" ago";
    }
  }
  
  var timeExtract = /approved by \w+ at (.+)/;
  var now = new Date().getTime();
  
  var checks = $(".approval-checkmark");
  checks.each(function(){
    var $this = $(this);
    var text = $this.attr("title");

    var match = text.match(timeExtract);
    if(match !== null) {
      var timestamp = match[1];
      var then = Date.parse(timestamp);
      var dt = now - then;
      var dtStr = timeAgoStr(dt);

      $this.attr("title", text+" ("+dtStr+")");
    }
  });
}))();