Time

An overview of the ISO 8601 notation for dates.

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.

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

History of standard time in the U.S.

Weights, measures and standard time.

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.