Fix Gmail Message Times When Resisting Fingerprinting (user script / pre-alpha)

gistfile1.txt

// ==UserScript==
// @name        Fix Gmail Message Times When Resisting Fingerprinting
// @author      Jefferson "jscher2000" Scher
// @namespace   JeffersonScher
// @version     0.1 Pre-Alpha
// @copyright   Copyright 2018 Jefferson Scher
// @license     BSD-3-Clause
// @include     https://mail.google.com/mail/*
// @grant       GM_registerMenuCommand
// ==/UserScript==

var UTCOffset = -7; // Your personal offset from UTC
var localePref = 'en-US'; // Your preferred locale for time format

var dtadj = UTCOffset * 1000 * 60 * 60;
var dnow = new Date(Date.now() + dtadj);

function fixTimes(){
  if (location.hash.indexOf('/') > -1) { // individual message?
    
  } else { // message list?
    var dtspans = document.querySelectorAll('td.xW.xY span[title]'), d, dtitle;
    for (i = 0; i < dtspans.length; i++){
      if (dtspans[i].getAttribute('title') == dtspans[i].getAttribute('aria-label')){
        d = new Date(Date.parse(dtspans[i].getAttribute('title').replace(' at', '')) + dtadj);
        dtitle = d.toDateString() + ' at ' + d.toLocaleTimeString(localePref);
        dtspans[i].setAttribute('title', dtitle);
        if (d.getMonth() == dnow.getMonth() && d.getDate() == dnow.getDate()){
          if (dtspans[i].innerHTML.indexOf('<b>') == 0) {
            dtspans[i].innerHTML = '<b>' + d.toLocaleTimeString(localePref).replace(':00 ', ' ') + '</b>';
          } else {
            dtspans[i].textContent = d.toLocaleTimeString(localePref).replace(':00 ', ' ');
          }
        } else {
          if (dtspans[i].innerHTML.indexOf('<b>') == 0) {
            dtspans[i].innerHTML = '<b>' + ['Jan ','Feb ','Mar ','Apr ','May ','Jun ','Jul ','Aug ','Sep ','Oct ','Nov ','Dec '][d.getMonth()] + d.getDate() + '</b>';
          } else {
            dtspans[i].textContent = ['Jan ','Feb ','Mar ','Apr ','May ','Jun ','Jul ','Aug ','Sep ','Oct ','Nov ','Dec '][d.getMonth()] + d.getDate();
          }
        }
      }
    }
  }
}
GM_registerMenuCommand("Tweak Dates", fixTimes);