Skip to Content


Home > Time

Time (Subscribe)



What is Time? popular

9 out of 10 stars (236 votes)

Time is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects. The temporal position of events with respect to the transitory present is continually changing; future events become present, then pass further and further into the past. Time has been a major subject of religion, philosophy, and science, but defining it in a non-controversial manner applicable to all fields of study has consistently eluded the greatest scholars. A simple definition states that "time is what clocks measure". Time is one of the seven fundamental physical quantities in the International System of Units. Time is used to define other quantities such as velocity so defining time in terms of such quantities would result in circularity of definition. An operational definition of time, wherein one says that observing a certain number of repetitions of one or another standard cyclical event (such as the passage of a free-swinging pendulum) constitutes one standard unit such as the second, is highly useful in the conduct of both advanced experiments and everyday affairs of life. The operational definition leaves aside the question whether there is something called time, apart from the counting activity just mentioned, that flows and that can be measured. Investigations of a single continuum called spacetime bring questions about space into questions about time, questions that have their roots in the works of early students of natural philosophy.

Review It Rate It Bookmark It

Z-Time popular

Article on the time at 0 degrees longitude. Covers the timezone origin, GMT, UTC, GCT, ZULU and JIG.

Review It Rate It Bookmark It

Wikipedia: Time popular

Time is a common term for the experience of duration, and a fundamental quantity of measuring systems. Article explains time definitions, history of measurements, perceptions in religion, philosophy and science.

Review It Rate It Bookmark It

Time Zone and Daylight Saving Time Data popular

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

Review It Rate It Bookmark It

Time FAQ popular

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

Review It Rate It Bookmark It

Time popular

Provides descriptions of several standards of time.

Review It Rate It Bookmark It

This Day In History popular

Today in history every day - often with pictures and sound.

Review It Rate It Bookmark It

NPR : 'Seize the Daylight': A History of Clock Chaos popular

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]

Review It Rate It Bookmark It

NIST Time and Frequency Division popular

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

Review It Rate It Bookmark It

Internet Encyclopedia of Philosophy: Time popular

Time has been studied for thousands of years. Nevertheless, many issues remain to be resolved. This article explores both what is now known about time and what is controversial and unresolved.

Review It Rate It Bookmark It

Infoplease: Daylight Saving Time popular

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

Review It Rate It Bookmark It

English Calendar popular

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

Review It Rate It Bookmark It

Calendar Zone popular

A categorized collection of calendar related sites.

Review It Rate It Bookmark It

Calendar Studies popular

Information about calendar history and calendar reform.

Review It Rate It Bookmark It

A Walk Through Time popular

Evolution of timekeeping through the centuries.

Review It Rate It Bookmark It

A History of Time popular

Explains the importance of concept of time in the history of mathematics, science and measurement.

Review It Rate It Bookmark It