Eighthour

Eighthour is a term used to describe one eighth of an hour. It denotes a time interval of 7.5 minutes, or 450 seconds, and is equivalent to 0.125 hours. There are eight eighthours in one hour.

In decimal and standard time notation, an eighthour can be represented as 0.125 hours or 7 minutes 30 seconds. This subdivision is not commonly used in everyday timekeeping, where minutes and seconds or decimal hours with smaller fractional steps are more typical. The concept may appear in theoretical discussions, instructional examples, or specialized time-tracking or payroll systems that experiment with nonstandard fractional increments.

Usage and context are generally limited. While the hour is universally divided into 60 minutes and the minute into 60 seconds, and many industries standardize on whole minutes or standard fractional hours (such as 0.25 or 0.5 hours), an eighthour remains a relatively obscure subdivision. It can serve as a convenience in illustrating fractional parts of an hour or in contexts that require uniform 7.5-minute blocks, but it is not a widely adopted unit in formal timekeeping.

Origin and terminology: the word eighthour is a straightforward English compound of “eighth” and “hour.” It is not part of official time nomenclature, but it can be used to describe a precise fraction of an hour in informal or specialized discussions.

See also: hour, minute, second, decimal time.