There are 2 previous versions of this script.
// ==UserScript==
// @id Indian railways/ IRCTC working realtime clock
// @name Indian railways/ IRCTC working realtime clock
// @namespace IRCTC_working_realtime_clock
// @author The Kalinga
// @description
// @include https://www.irctc.co.in/*
// ==/UserScript==
if (document.getElementById('orngnavi')){
var window = unsafeWindow || window;
var anchorHoldingTime = document.evaluate('//a[contains(., "GMT+05:30") or contains(., "IST")]', document.getElementById('orngnavi'), null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null).snapshotItem(0);
var dateMatcherRegEx = /(\d{2}-[A-Z][a-z]{2}-\d{4}) \[(\d{2}:\d{2}:\d{2}) ((GMT\+05:30)|(IST))\]/g;
var matches = dateMatcherRegEx.exec(anchorHoldingTime.text.trim());
var capturedTime = new Date(anchorHoldingTime.text.trim().replace(/\[|\]|IST|GMT\+05:30/g, '').replace(/-/g, ' '));
var millisSince1Jan1970 = capturedTime.getTime();
anchorHoldingTime.innerHTML = matches[1]+' [<span>'+matches[2]+'</span> '+matches[3]+']';
var tickingSpan = anchorHoldingTime.getElementsByTagName('span')[0];
window.updateTime = function updateTime(){
millisSince1Jan1970 += 1000;
tickingSpan.innerHTML = new Date(millisSince1Jan1970).toLocaleTimeString();
}
setInterval("updateTime()",1000);
}