Query MongoDB Stitch API for Data from A Google Apps Script - maintaining timeout to avoid overloading API

fetchData.js

/**
|* Insert this code into your Google Sheets Script Editor
|* From there, you can insert into a cell in the sheet =fetchCode("somevalue")
|* This will return the value fetched from the database and set a last date fetched.
|* Next time you want to fetch - it will compare the last date fetched. If it's more than a day
|* It will fetch again - otherwise, not.
**/

function fetchCode(code) {
    if (!code || code == "") {
        return;
    }
    var codeProperties = PropertiesService.getUserProperties();
    if (codeProperties.getProperty(code)) {
        var days = diffInDays(codeProperties.getProperty(code), new Date())
        Logger.log("Days since update: " + days);
        if (days < -1) {
            return; // too soon.
        }
    } else {
        codeProperties.setProperty(code, new Date())
        Logger.log("Set date to " + new Date());
    }
    // change this url to the url you created from your 3rd party http webhook
    var url = "https://webhooks.mongodb-stitch.com/api/client/v2.0/app/<stitch-app-id>/service/api/incoming_webhook/api?param=" + code + "&secret=<YOURSECRE>";
    var response = UrlFetchApp.fetch(url, { 'muteHttpExceptions': false });
    if (response != false) {
        var data = JSON.parse(response.getContentText());
        if (data.length > 0) {
            var remaining = data[0].credits[0].remaining_amount_dollars.$numberDouble;
            Logger.log("Remaining: " + remaining);
            return remaining;
            //Get the date
            var json = response.getContentText();
            if (!Array.isArray(json)) {
                json = [json];
            }
        } else {
            return;
        }
    }
}
/*
|* Compare two dates
*/
function diffInDays(d1, d2) {
    var dt1 = new Date(d2), // today's date
        dt2 = new Date(d1); // your date from API

    // get milliseconds
    var t1 = dt1.getTime(),
        t2 = dt2.getTime();

    var diffInDays = Math.floor((t1 - t2) / (24 * 3600 * 1000));
    // 24*3600*1000 is milliseconds in a day
    console.log(diffInDays);
    return diffInDays;
}