if (expireDateTime) {
                // the things we do for backwards compatibility...
                // in ECMA-262 5th ed., we could simply use:
                //     while (Date.now() < expireDateTime) { }
                do {
                    now = new Date();
                } while (now.getTimeAlias() < expireDateTime);
            }

setHeartBeatTimer: function (minimumVisitLength, heartBeatDelay) {
    var now = new Date();

    configMinimumVisitTime = now.getTime() + minimumVisitLength * 1000;
    configHeartBeatTimer = heartBeatDelay * 1000;
},

lastActivityTime = now.getTime();
setTimeout(function heartBeat() {
    var requestPing;
    now = new Date();

    // there was activity during the heart beat period;
    // on average, this is going to overstate the visitDuration by configHeartBeatTimer/2
    if ((lastActivityTime + configHeartBeatTimer) > now.getTime()) {
        // send ping if minimum visit time has elapsed
        if (configMinimumVisitTime < now.getTime()) {
            requestPing = getRequest('ping=1', customData, 'ping');

            sendRequest(requestPing, configTrackerPause);
        }

 if (String(orderId).length) {
     request += '&ec_id=' + encodeWrapper(orderId);
     // Record date of order in the visitor cookie
     lastEcommerceOrderTs = Math.round(now.getTime() / 1000);
 }