Google has scrapped a planned 13-hour maintenance session to the online Google Calendar service that had some users confused and worried.

Apparently, Google decided to cancel the maintenance work after hearing from enough concerned users of Google Calendar, and of the Google Apps hosted applications suite of which it is part.

"Google is focused on its users, and in this case we listened to user feedback in making our decision," a Google spokesman said.

Google notified Google Apps administrators that it planned to conduct "routine maintenance" of Calendar between 8 am and 9 pm on 26 April Thursday, but it did not specify a time zone, leading some users to post messages in discussion forums seeking clarification.

Others posted messages expressing concern about the length of service disruptions, which was not addressed in the initial email, particularly because the maintenance work was scheduled during a weekday and during work hours.

IT maintenance work that takes services offline is usually done during weekends or, if done during weekdays, very late at night.

Subsequently, Google sent these administrators another email, clarifying that the first email referred to Pacific Time and that end users might find Calendar unavailable for no more than 5 or 10 minutes during this 13-hour window.

However, Google is now saying the maintenance work has been scrapped, and that future work of this type in Calendar will be coordinated in a way that does not affect Google Apps users at all, according to the spokesman.

The incident has also triggered a review of how Google Apps software is maintained in the future. "We are actively working on changes in routine maintenance procedures for other products on the Google Apps platform, so updates such as these will either take place outside of peak hours or not impact our customers at all. We are sorry for any confusion this has caused," the spokesman wrote.