Google Analytics had a bug that resulted in about an hour of lost data on October 18th. That data is unrecoverable and you should note, maybe with an annotation, that there was a glitch resulting in less data being collected by Google Analytics.

Many of us saw the issue when looking at the real time Google Analytics dashboard on October 18th, I even tweeted about it:

Daniel J. Pinna noticed the data seemed to have not been backfilled so he followed up with Google who told him that the data is lost between 7:27am and 8:30am PDT on October 18, 2021.

Here is what Google told him:

He also posted this information at WebmasterWorld.

So if you see a weird data void glitch in your Google Analytics reporting on October 18th – that is why.

Forum discussion at WebmasterWorld and Twitter.