Week (wk) - Unit Information & Conversion
What is a Week?
Definition
A week is a unit of time equal to seven days. It is not an SI unit but is widely used as a convenient cycle for organizing activities longer than a day but shorter than a month.
History
The seven-day week has origins in ancient Babylonian astronomy, linked to the seven classical celestial bodies visible to the naked eye (Sun, Moon, Mars, Mercury, Jupiter, Venus, Saturn). This system was adopted by the Jews and later spread through Christianity and Islam. While other cultures have used different week lengths throughout history, the seven-day week became dominant globally, particularly with the adoption of the Gregorian calendar.
Common Uses
- Scheduling: Organizing work schedules (work week vs. weekend), school schedules, social events, and appointments.
- Calendars: The fundamental structure block in most modern calendars.
- Planning: Used for short-term planning of tasks, projects, holidays, and recurring events.
- Cycles: Measuring durations like project phases, rental periods, medication schedules, or publication frequencies (weekly magazines).
- Cultural/Religious Observance: Many cultures and religions observe specific days of the week for rest, worship, or specific activities (e.g., Sabbath, Sunday).
Unit FAQs
How many days are in a week?
There are 7 days in a week.
How many hours are in a week?
There are 168 hours in a week (7 days * 24 hours/day).
Is the week an official SI unit?
No, the week is not part of the International System of Units (SI). The base unit of time is the second.
Where did the seven-day week come from?
It is believed to originate with the ancient Babylonians, who associated the number seven with the seven visible celestial bodies (Sun, Moon, and five planets).
Week Conversion Formulas
To Second:
To Minute:
To Hour:
To Day:
To Month:
To Year:
To Millisecond:
To Microsecond:
To Nanosecond:
To Decade:
To Century:
To Millennium:
To Fortnight:
To Planck Time:
To Shake:
To Sidereal Day:
To Sidereal Year:
Convert Week
Need to convert Week to other time units? Use our conversion tool.