National Journal Daybook — a compendium of upcoming U.S. government, NGO and relevant academic activity
Council on Foreign Relations Calendar — a guide to international happenings
United Nations Calendar — another guide to international events
2 Chambers Blog — Washington Post blog that details upcoming Capitol Hill events at the start of the week.
Free Speech TV Calendar — an outlook for progressive events
DC Indy Media — calendar of local events highlighted by DC IndyMedia
The Progressive — provided a paper calendar of historical events
SCOTUS Blog Calendar — an overview of pending U.S. Supreme Court activity