How to Use Timer Triggers in Google Tag Manager [V2]

Event Listeners have been an extremely useful feature in Google Tag Manager, making it easy to capture on-page interactions like link clicks, downloads, button clicks, and form submissions. By listening for events and sending data to GA, you can get more detailed and more precise information about how people are using your site.

In GTM’s Version 2 interface, listening for events is now more efficient than ever.

Instead of requiring both a Listener tag and a firing Rule as before, listening for an event can now be accomplished with a single Trigger. (In V2, triggers are the upgraded version of rules.) Hence, a trigger can now be used to both listen for an event and fire the desired tracking tags as a result.

We had previously written a tutorial on How to Use Timer Listeners in Google Tag Manager. We can now do the same with Timer triggers in GTM Version 2.

The most common way that we use Timer triggers is to track the time a user spends on a particular page. Wait, doesn’t Google Analytics track Time on Page automatically? Well, yes and no. GA calculates time spent on a given page by taking the difference between the timestamp of that pageview and the timestamp of the subsequent hit. But if a pageview is the last (or only) hit in the session, GA will assign it a time of zero.

That’s where Timer triggers come in! If you’re using GTM (and if you’re not, you should be), Timer triggers give you a simple way to get more precise metrics for time on page, session duration, and bounce rate in Google Analytics.

Let’s now take a look at how to implement Timer triggers in GTM Version 2.

Basic Implementation

1. To get started, you will need to have a Google Tag Manager account (in the version 2 interface) and permissions to edit your website’s GTM container.
2. Create the Timer trigger as follows:
   1. Add a new trigger. Choose Timer as the event type.
   2. Enter the desired timer interval in milliseconds, e.g. For a 30 second timer, enter 30000, and set the timer limit to 1 (For recurring timers, see Advanced Implementation instructions below).
   3. Enable the timer trigger on all pages by using the condition Page URL matches RegEx .* or enable on a subset of target pages.
   4. Set the trigger to fire on All Timers.
3. Create a new Universal Analytics event tag. Enter appropriate values for at least Event Category and Event Action. Set the tag to fire on the timer trigger you created.

That’s it! You can now use GTM’s Preview & Debug mode to see your new tag in action. Once you are happy with the configuration, save a new container version and publish.

Advanced Implementation

Now, let’s crank it up a notch. What if you want to record multiple timer events from the same timer? A single 30 second timer is better than nothing, but what if visitors are spending 5, 10, or as much as 20 minutes on a single page before leaving your site? With only a 30-sec timer, your session duration metric could still be hugely misleading.

Here is an implementation strategy to fire recurring timer events every 30 seconds and appropriately label those events in GA:

1. As above, you will need access to your GTM container.
2. Create the Timer trigger.
   1. Add a new trigger. Select Timer as the event type.
   2. Set the timer interval as above, but leave the limit field blank. This will allow the timer listener to fire indefinitely until the user leaves the page or closes their browser.
   3. Since a recurring timer will generate a lot of events, in step 3, you may only wish to enable this trigger on certain pages, e.g. your home page, articles and blog posts, or other pages that have high exit rates.
3. Create two new variables to capture the timerEventNumber and timerInterval auto-event variables as follows. At least right now, GTM does not create these macros by default:
   1. Create a new variable named timerEventNumber, set to the value of the gtm.timerEventNumber variable in the data layer. This will return the count of the number of times that the timer listener has fired on the page. 
   2. Create a new variable named timerInterval exactly as above, but with gtm.timerInterval as the data layer variable name. This will return the timer interval that you have specified in the listener tag.
4. Configure your Universal Analytics event tag as follows,where {{timerEventLabel}} is a custom JavaScript variable defined as:

   function() {
     var elapsed = {{timerEventNumber}} * {{timerInterval}} / 1000;
     var min = Math.floor(elapsed/60);
     var sec = elapsed % 60;
     return min + 'm ' + sec + 's';
   }

   The timerEventLabel macro returns the elapsed time in minutes and seconds, based on timerEventNumber and timerInterval.

5. Save, test, and publish!

You can of course modify the variable names or interval length to better match your current website and GTM implementation.

For more information, check out the Google Analytics Help Centre article about Triggers in Google Tag Manager [V2].

Let us know what you think about Timer triggers and how you are utilizing them in GA!