http://www.fema.gov/emergency/ipaws/eas_info.shtm

 

2pm EST. Test will run for 3 minutes. Should it work properly you will see a message that will say "this is a test". If it doesn't work right, you may not see anything, but just here the usual noises. The reason they are warning folks is for the latter so they don't assume anything is amiss.

Cool, I think this is a good thing. I see the local tests all the time but the whole country at once is a good thing in case a SHTF scenerio.