Hours (h)
An hour is a unit of time equal to 3600 seconds or 60 minutes. It is a non-SI unit accepted for use with the International System of Units based on the division of the day into 24 equal parts. The hour is standardized internationally and used universally in timekeeping, scheduling, and scientific measurements [bipm-si-brochure].
Origin
The division of the day into 24 hours originated with ancient Egyptians and Babylonians. The modern hour was formalized with the adoption of mechanical clocks in medieval Europe and standardized internationally by the CGPM in the 20th century [cgpm-resolutions].
Worldwide Use
Hours are the fundamental unit of time measurement globally, used in daily life, transportation, scientific research, and industry. It is recognized by all standards bodies including ISO and NIST and forms the basis for time zones and scheduling worldwide [nist-sp-811].
Common References
- One hour equals 60 minutes
- Typical work shifts last 8 hours
- A standard movie length is about 2 hours
- Hourly weather forecasts update every hour