Google Apps Script is a serverless environment that makes it easy for you to work with Gmail, Google Drive and other services that are part of the Google Workspace platform.

When you run any code inside the Google Apps Script IDE, in simple English, it spins up a new server with the required environment that are necessary to run your application. This server is allotted a hard timeout limit and the App Script environment will halt the execution of the function if it exceeds the maximum execution time.

Exceeded maximum execution time

The maximum execution time varies based on the type of your Google Account. If you are running your Apps Script code inside a Gmail account, your functions can run for 6 minutes before it will be terminated. For Google Workspace accounts, because you are paying a monthly fee to Google per user, the timeout limit is more generous at 30 minutes.

If your Apps Script function / trigger exceeds the maximum timeout limit, the script will throw an exception like Exceeded maximum execution time or equivalent based on your script’s locale.

Exceeded maximum execution time
Se ha superado el tiempo máximo de ejecución.
Timpul maxim de executare a fost depășit
تجاوز الحد الأقصى لعدد مرات التنفيذ
Vượt quá thời gian thực thi tối đa
Durée d'exécution autorisée dépassée
Przekroczono maksymalny czas wykonywania
Limite massimo del tempo di esecuzione superato
เวลาประมวลผลเกินขีดจำกัดสูงสุด
Melebihi jumlah eksekusi maksimum
Превышено максимально допустимое время выполнения
Lumagpas sa maximum na oras ng execution

Avoid Maximum Execution Time Limit

You can include a simple time check in your Apps Script function, that it likely to take more than a few minutes to execute, and gracefully pause the request if is seen to be exceeding the time limit.

For instance, the Download Gmail add-on saves email messages from Gmail to Google Drive as PDF files. It grabs a bunch of messages from the Inbox, converts them to PDF and runs in a loop. If the execution is taking longer, it breaks from the loop automatically.

const GMAIL_USER = /(gmail|googlemail)/.test(Session.getActiveUser().getEmail());
const ONE_SECOND = 1000;
const ONE_MINUTE = ONE_SECOND * 60;
const MAX_EXECUTION_TIME = ONE_MINUTE * (GMAIL_USER ? 6 : 30);
const NOW = Date.now();

const isTimeLeft = () => {
  return MAX_EXECUTION_TIME > Date.now() - NOW;
};

const thisFunctionTakesTimeToExecution = () => {
  const threads = GmailApp.getInboxThreads(0, 100);
  for (let t = 0; t < threads.length && isTimeLeft(); t += 1) {
    // Save email to Google Drive
    Logger.log('Saving email...');
  }
};