Triggering Apps Scripts Automatically (Time-Driven & Event-Driven) in Google Sheet

Ever wish your Google Sheet could do some of the work for you — like sending a reminder email, updating a dashboard, or moving data — without you clicking a thing? That’s exactly what Apps Script triggers are for! They let your script run automatically, based on a schedule or an action like editing a cell. If you’re just starting out with Google Sheets, learning how to use these triggers can save you tons of time and manual effort. Let’s break it down in a simple, beginner-friendly way.

What Are Apps Script Triggers?

Apps Script triggers are tools that tell your code when to run — either based on time (like every day at 9 AM) or actions (like opening the file or editing a cell). You don’t need to click a button — it just happens in the background. Pretty neat, right?

Two Types of Triggers

• Time-Driven Triggers: Run scripts on a schedule — like every hour, daily, or weekly.
• Event-Driven Triggers: Run scripts when something happens — like someone opens the sheet or edits a cell.

Why Use Triggers in Google Sheets?

Imagine these benefits:

• Send automatic email reminders to your team.
• Backup your data daily without lifting a finger.
• Clean up or reformat data every time someone edits the sheet.
• Automate reports — no more manual copy-paste!

Real-Life Example: Daily Task Reminder Email

Let’s say you manage a small team using Google Sheets to track tasks. Every morning, you want an email listing all tasks that are still “Pending.” You can set up a time-driven trigger to send that email daily without any manual steps.

Sample Sheet: Task Tracker

Task	Assigned To	Status
Update Website	Alice	Pending
Send Invoice	Bob	Completed

How to Set Up a Time-Driven Trigger (Step-by-Step)

1. Open your Google Sheet.
2. Click Extensions > Apps Script.
3. Paste your script (like sending an email based on sheet data).
4. Click the clock icon on the left panel (Triggers).
5. Click + Add Trigger.
6. Choose the function you want to run.
7. Select event source: Time-driven.
8. Choose type: Day timer > 8am to 9am (or your preferred schedule).
9. Click Save.

How to Set Up an Event-Driven Trigger

These run automatically when someone edits the sheet or opens it.

1. In your Apps Script, write a function named onEdit(e) or onOpen().
2. These special function names are recognized by Google — no need to add a trigger manually.

Example: Automatically Highlight Overdue Tasks

function onEdit(e) {
  var sheet = e.source.getActiveSheet();
  var range = e.range;
  if (range.getColumn() == 3 && range.getValue() === "Overdue") {
    range.setFontColor("red").setFontWeight("bold");
  }
}

Pro Tips for Using Triggers

• Only simple triggers like onEdit() and onOpen() don’t need manual setup.
• For sending emails or accessing other services, use an installable trigger (set up through the Triggers tab).
• Debug your function by running it manually first to check for errors.
• Check trigger logs under Apps Script Dashboard > Triggers if something goes wrong.

Trigger Cheat Sheet (Quick Reference)

Trigger Type	When It Runs	Setup Method
onOpen()	Every time the spreadsheet is opened	Write a function named onOpen()
onEdit(e)	Every time a cell is edited	Write a function named onEdit(e)
Time-driven	Scheduled (e.g., daily at 9 AM)	Set up via Triggers panel
Form Submit	When a Google Form linked to a sheet is submitted	Set up via Triggers panel

Triggers in Google Apps Script let your spreadsheet work for you — on autopilot. Whether you want to send emails every morning or instantly react to changes in your data, time-driven and event-driven triggers are your go-to tools. They’re simple to set up and powerful enough to handle everyday tasks.

Start small — try setting up a daily email or highlighting edits — and you’ll soon be automating like a pro. Happy scripting!