Huffington Post reports that Gmail also went offline on April 29th of 2010.

http://www.huffingtonpost.com/2010/04/29/gmail-down-check-gm...

Google reports that Gmail also went offline on April 24th of 2009.

http://googleblog.blogspot.com/2009/02/current-gmail-outage....

(Sadly, the partial Gmail outage of 2011 seemed to be February 27th, or this would be an epic pattern of "don't trust Gmail during the end of April" ;P.)

http://www.eweek.com/c/a/Messaging-and-Collaboration/Google-...