time zone clock

Description:	United States Code - Weights, measures and standard time
URL:	http://tycho.usno.navy.mil/260.html

Description:	Date Algorithms - Provides descriptions, proofs and computer programming implementation examples to convert dates to various calendar dates for Julian, Gregorian, and Rata Die calendars
URL:	http://vsg.cape.com/~pbaum/date/date0.htm

Description:	Calendar: A History - The history of the western calendar and the clock
URL:	http://www.ernie.cummings.net/calendar.htm