I checked the MousePlanet weekly updates, and here are some previous dates that IASW was down (being refurbed) to install the Holiday overlay:
Oct 20 to Nov 7, 2003
Oct 18 to Nov 4, 2004
Oct 24 to Nov 10, 2005
Oct 23 to Nov 9, 2006
Oct 22 to Nov 8, 2007
And like Sherry wrote above, IASW was down from Jan to Nov 2008 for a major refurb.
HTH