Explains the differences between several time systems.

An illustrated history of timekeeping from ancient times to the present.

Displayed in a variety of useful formats. Site is a front-end to U.S. government atomic clocks.

Information about calendar history and calendar reform.

A categorized collection of calendar related sites.

A history of the western calendar, including the Gregorian and Julian and Roman Calendars, and how the days of the week and months got their names, and a history of time.

Provides descriptions, proofs and computer programming implementation examples to convert dates to various calendar dates for Julian, Gregorian, and Rata Die calendars.

Includes an ecclesiastical calendar and a section on old and new style dating.

Information and history about Daylight Saving Time all over the world.

International Standard ISO 8601 specifies numeric representations of date and time. It helps to avoid confusion caused by the many different national notations.

Shedding light on Queensland's daylight saving opposition.

The National Institute of Standards and Technology maintains time and frequency standards for the United States.

Benjamin Franklin first called for the government to tinker with clock hours in the 1780s. But it wasn't until World War I that the United States adopted daylight-saving time as a way to get more efficiency out of the day. "Seize the Daylight" Author David Prerau talks about the complicated politics and curious history of DST, and he shares an excerpt from his book. [4:54 streaming audio broadcast]

Summarizes the history of various calendars developed and used over the centuries.

Highlights one major event in recent times, and provides a short list of past events. Also features special entries about this day in crime, entertainment, literary, war, technology, and automotive history.

Provides descriptions of several standards of time.

Frequently Asked Questions about time (from sci.astro news group)

To set your watch or clock accurately using a time reference. Explains the various options for residents of North America.

A directory of sites providing descriptions of civil timekeeping concepts, source code, databases, and maps.

Information on all things relating to calendars, dates, holidays, and time. Find today's date on several different cultural and religious calendars. Includes section on Celestial data, countdown clocks, and information on the dates past events.

History of standard time in the U.S.

Weights, measures and standard time.