Looking for help adding a timestamp custom dimension to Google Analytics.

I've managed to add a timestamp javascript to one of the sites. It appears on the GA dashboard but isn't collecting data.  

Since it already viewable in GA dashboard, it should working fine. Can you share with us what you mean by "isn't collecting data"?

You can add the GA custom dimension for timestamp via javascript or Google Tag Manager(GTM).
If the connecting isn’t working, make sure you have disable any kind of adblockers like AdBlock or Ghostery before check again your GA result.

Cross-check the steps if anything misses out in your configuration:
https://sandervolbeda.com/add-timestamp-to-google-analytics/

Thank you, David.

When I view the standard Page View report, it shows activity. But when I select the Timestamp custom dimension, all values in the page view table are cleared and replace with a single row of zeroes.

I had followed the video which was at the bottom of the article you shared, but I had not completed the steps related to this: 

1. Check: Enable overriding settings in this tag

So I checked that box, entered the Universal Analytics tracking ID, and hope that fixes the issue.

Unfortunately, the Tag Manager Preview says that it detects a legacy js tag for the site I'm monitoring. I'm not sure why, since it seems to be current, but I can't get beyond that message in Preview to see anything else. I'll check Google Analytics tomorrow to see if data is now being displayed with Timestamp.

--Rick 

Unfortunately, the Tag Manager Preview says that it detects a legacy js tag for the site I'm monitoring. I'm not sure why, since it seems to be current, but I can't get beyond that message in Preview to see anything else. I'll check Google Analytics tomorrow to see if data is now being displayed with Timestamp. 

Well noted. Awaiting your good news and please share with us if you need any further assistance for this topic.

David, I'm making some progress by starting fresh with another microsite. A couple of quick questions.

Would you verify that the Google Analytics tracking ID in step 3.3 from https://sandervolbeda.com/add-timestamp-to-google-analytics/ below should be the UA ID?

3.2 Check: Enable overriding settings in this tag
3.3 Add the Google Analytics tracking ID manually

Also, I'd like to verify that only the ID should be entered. If I click on the camera icon, it brings up a list of Variables that can be added.

The reason I ask is, there is no "Variables" tab in the GA Tag Assistant for Universal Analytics, just "Hits Sent" "Data Layer" and "Errors".

"Variables" does appear if the GTM ID is selected, and it shows the Timestamp variable – but "Return Type" and "Value" are both "undefined" – I assume because I've entered the UA ID in step 3.3 above.