A very useful source for calendar info regarding events here in D.C. (from Congressional events, to statistical releases to think tanks issuing reports) is the Washington Daybook from Find-Inc. The Daybook is also published each morning in the Washington Times at this URL:

http://www.washingtontimes.com/national/daybook.htm

If you look near the top or bottom of the page, you can even have the page spoken to you using the Washington Times "Click-2-Listen" service.

Here's an example.

Links to the last 5 daybooks are found at the bottom of the page.

If you're interested in archiving each Daybook page for the long term, you might want to consider using a web clipping service like eSnips that offers 5GB of free online storage and sharing space.

Btw, on our ResourceShelf site, we've collected a number of planning calendars that might be of interest from the BBC, UN, APTV, and other sources.