International Standard Date and Time Notation
An overview of the ISO 8601 notation for dates.

This Day In History
Today in history every day - often with pictures and sound.

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

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

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

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

Time Zone and Daylight Saving Time Data
A directory of sites providing descriptions of civil timekeeping concepts, source code, databases, and maps.

A Walk Through Time
Evolution of timekeeping through the centuries.

When Do You Want To Go Today?
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.

Calendar Zone
A categorized collection of calendar related sites.

United States Code
Weights, measures and standard time.

Time
Provides descriptions of several standards of time.

U.S. Time Zones
History of standard time in the U.S.

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

Calendar: A History
The history of the western calendar and the clock.

Calendar Studies
Information about calendar history and calendar reform.

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

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

A Few Facts Concerning GMT, UT, and the RGO
Explains the differences between several time systems.

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

Light of Day
Shedding light on Queensland's daylight saving opposition.