Daylight Saving Time [ Profile ] - Why do we use daylight savings time and who invented it?

	International Standard Date and Time Notation [ Profile ] - International Standard ISO 8601 specifies numeric representations of date and time. It helps to avoid confusion caused by the many different national notations.

	Latitude and Longitude [ Profile ] - Introduction to latitude and longitude, a way of calculating exactly where you are anyplace on earth and a way to tell time.

	Make Your Own Star Clock [ Profile ] - Learn how to tell time by finding constellations in the night sky.

	Making a Sun Clock [ Profile ] - Before there were clocks, people used shadows to tell time. Learn how to make your own sun clock!

	Making a Horizontal Sundial [ Profile ] - Learn how to make a sundial. Instructions are for beginners, intermediate, or advanced, and work for either the northern or southern hemispheres.

	Time [ Profile ] - Just how do we measure time and what has Greenwich England got to do with it?

	Time Travel [ Profile ] - Is time travel possible? See what Carl Sagan and Einstein had to say about time travel in this NOVA special.

	A Walk Through Time [ Profile ] - An illustrated history of timekeeping from ancient times to the present.

	What Time Is It! [ Profile ] - Gives the current time, synchronized by NIST. Close to 100 different time zones supported, as well as the ability to select the default time zone.

	World Time Converter [ Profile ] - Provides online times converter and brief information about GMT/UTC.

	Local Times Around the World [ Profile ] - Find out what time it is anywhere in the world.

	NPR : 'Seize the Daylight' [ Profile ] - Talks about the complicated politics and curious history of daylight standard time.

	Countdown [ Profile ] - Calculate the exact time in days, hours, minutes and seconds from now until your birthday or any other event.

	When Does Daylight Savings Time Occur [ Profile ] - Explanation of when and why we have daylight savings time.

	On Time [ Profile ] - Learn about the history of time measuring devices in this online Smithsonian Institute exhibit. Page discusses how the accuracy of watches and clocks affected people's perception and usage of time.

	A History of Time [ Profile ] - A two-part article that discusses physicist's evolving view of time.

	National Geographic Kids Magazine: Water Clock Experiment [ Profile ] - Demonstrates how water clocks can be used to keep time.

	Discover - Time Machine [ Profile ] - Article explores a clock designed to keep accurate time for 10,000 years.

	How Stuff Works: Time [ Profile ] - Complete five-part explanation of time and how it is measured, including information about clocks, time zones, and calendars.

	The Galileo Project - Pendulum Clock [ Profile ] - Describes Galileo's work on pendulums and the pendulum clock.

	The Hourglass [ Profile ] - The University of Houston College of engineering, describes how an hourglass works and also provides interesting facts about this timekeeper.

	Industrious Clock [ Profile ] - Clock using video of a hand drawing to display the time.

	US Library of Congress - How does an hourglass measure time? [ Profile ] - Answers questions about how an hourglass keeps time and what are the contributing factors determining how long an hourglass lasts.