6/18/2014 Google Apps Calendars Service Disruption

At 2:58 pm EST Google reported an issue with Google Calendars. Affected users see message "sorry you have been logged out probably in another window" on the Web client and the session is terminated.

More information on this can be found at the Google Apps Status Dashboard or the Known Issues of the Enterprise Support Center

Update: As of 4:40 pm EST Google has reported that this issue should be resolved.