Credit: CC0 Public Domain

Hopefully you remember when and where your next appointment is.

That's because the widely used Google Calendar was down on Tuesday morning.

Users trying to access Google Calendar from their computers instead received a "Not Found Error 404" message.

Google acknowledged the with a post at 10:22 AM:

"We're investigating reports of an issue with Google Calendar. We will provide more information shortly. The affected are unable to access Google Calendar."

At least some users were still able to access the calendar through their mobile phones.

Other Google services, including Gmail, were apparently unaffected.

That was not the case earlier this month when a Google Cloud outage knocked out Gmail, YouTube and other sites.

This latest disruption is worldwide.

At the Downdetector.com website, comments on Google Calendar being down came from as far away as Croatia, Portugal, Brazil and the Czech Republic, as well as all across the U.S.

Google has not yet responded to a U.S. TODAY request for comment on the possible cause of the outage and or when the Calendar might again be up and running.

The timing of the outage is especially embarrassing for Google given that the Calendar went down shortly after the official G Suite Twitter account tweeted a message: "Scheduling made simpler @googlecalendar."

The promise of simpler scheduling will have to wait.