Precision: The Official U.S. Time

Depending on what kind of stickler you are about being on time, this site from the National Institute of Standards and Technology and the U.S. Naval Observatory could be just the ticket. The official U.S. government time -- accurate to within 1 second -- for time zones in the the U.S. and its territories is displayed in large, easy-to-read numerals, along with the coordinated universal time and a world map displaying where the sun is shining. "Time Exhibits" have info about Daylight Saving Time, calendars, clocks, watches, timekeeping, et cetera. <http://www.time.gov/>