April 15th, 2009 | Published in Google Adwords
On Saturday, April 18th, 2009, the AdWords system will be unavailable from approximately 10 a.m. to 2 p.m. PST due to system maintenance. While you won't be able to sign in to your accounts during this time, your campaigns will continue to run as usual. We apologize for any inconvenience.
Posted by Austin Rachlin, Inside AdWords crew