Tens of thousands of items are now available for two-hour delivery from 8 a.m. to midnight, seven days a week, the company says.

Zip codes across the Anacostia River aren’t eligible.

Courtesy Amazon.com Online retail giant Amazon.com today launched same-day delivery in select cities, and Washington, D.C. is one of them. The service, dubbed “Local Express Delivery,” has also been extended to customers in New York, Philadelphia, Boston, Baltimore, Las Vegas, and Seattle, and will be launched in Chicago, Indianapolis and Phoenix in a few months. Before you rush off to place an urgent order for that Slanket you’ve finally conceded you want, here’s how…