Twilight

A conversion service for turning sun and twilight data from the Astronomical Applications Department of the U.S. Naval Observatory into RDF.

This service understands the Accept: header - if it contains application/rdf+xml, or if the RDF/XML checkbox is checked, it will return a simple RDF/XML document.

See also: nearestAirport, Automatically Generating Metadata for Digital Photographs with Geographic Coordinates and other papers by Mor Naaman et al.